Arrhythmia-Critical Care IV semester

Correct Answer: 2 Rationale 1: A first-degree AV block is not a life-threatening dysrhythmia and defibrillation is not necessary. Rationale 2: This is first-degree AV block. There is no action necessary for this dysrhythmia. Rationale 3: This is not a life-threatening dysrhythmia, and the healthcare provider does not need to be notified. Rationale 4: Sublingual nitroglycerin is used for chest pain. Global Rationale: This is a first-degree AV block. There is no action necessary for this dysrhythmia. This is not a life-threatening dysrhythmia. Defibrillation is not necessary. The healthcare provider does not need to be notified. Sublingual nitroglycerin is used for chest pain.

A patient in the coronary care unit has the following cardiac rhythm: What action should the nurse take when caring for this patient? 1. Prepare to defibrillate. 2. Monitor for any changes. 3. Notify the healthcare provider. 4. Administer a dose of sublingual nitroglycerin.

The patient's heart rhythm shows an inverted P wave with a PR interval of 0.06 seconds. The heart rate is 54 beats per minute. The nurse recognizes the rhythm is due to the a. loss of sinus node activity. b. increased rate of the AV node. c. increased rate of the SA node. d. decreased rate of the AV node.

ANS: A Junctional escape rhythm occurs when the dominant pacemaker, the SA node, fails to fire. The normal heart rate of the AV node is 40 to 60 beats per minute, so the AV node rate has neither increased nor decreased. P waves may be inverted. An increased SA node rate would override the AV node.

The patient is having premature ventricular contractions (PVCs). The nurse's greatest concern should be: a. the proximity of the R wave of the PVC to the T wave of a normal beat. b. the fact that PVCs are occurring, because they are so rare. c. whether the number of PVCs is decreasing. d. whether the PVCs are wider than 0.12 seconds.

ANS: A The peak of the T wave through the downslope of the T wave is considered the vulnerable period, which coincides with partial repolarization of the ventricles. If a PVC occurs during the T wave, ventricular tachycardia may occur. When the R wave of PVC falls on the T wave of a normal beat, it is referred to as the R-on-T phenomenon. PVCs may occur in healthy individuals and usually do not require treatment. The nurse must determine if PVCs are increasing in number by evaluating the trend. If PVCs are increasing, the nurse should evaluate for potential causes, such as electrolyte imbalances, myocardial ischemia or injury, and hypoxemia. Runs of nonsustained ventricular tachycardia may be a precursor to the development of sustained ventricular tachycardia. Because the stimulus depolarizes the ventricles in a slower, abnormal way, the QRS complex appears widened and has a bizarre shape. The QRS complex is wider than 0.12 seconds and often wider than 0.16 seconds.

The nurse using cardiac monitoring understands that each horizontal box on the electrocardiogram (ECG) paper indicates a. 200 milliseconds or 0.20 seconds duration. b. 40 milliseconds or 0.04 seconds duration. c. 3 seconds duration. d. millivolts of amplitude.

ANS: B ECG paper contains a standardized grid where the horizontal axis measures time and the vertical axis measures voltage or amplitude. Horizontally, the smaller boxes denote 0.04 seconds each or 40 milliseconds; the larger box contains five smaller boxes and thus equals 0.20 seconds or 200 milliseconds.

The nurse is examining the patient's cardiac rhythm strip in lead II and notices that all of the P waves are upright and look the same except one that has a different shape and is inverted. The nurse realizes that the P wave with the abnormal shape is probably a. from the SA node because all P waves come from the SA node. b. from some area in the atria other than the SA node. c. indicative of ventricular depolarization. d. normal even though it is inverted in lead II.

ANS: B Normally a P wave indicates that the SA node initiated the impulse that depolarized the atrium. However, a change in the shape of the P wave may indicate that the impulse arose from a site in the atria other than the SA node. The P wave represents atrial depolarization. It is usually upright in leads I and II and has a rounded, symmetrical shape. The amplitude of the P wave is measured at the center of the waveform and normally does not exceed three boxes, or 3 millimeters, in height.

The nurse notices ventricular tachycardia on the heart monitor. When the patient is assessed, the patient is found to be unresponsive with no pulse. The nurse should a. treat with intravenous amiodarone or lidocaine. b. begin cardiopulmonary resuscitation and advanced life support. c. provide electrical cardioversion. d. ignore the rhythm because it is benign.

ANS: B Ventricular tachycardia (VT) is a rapid, life-threatening dysrhythmia originating from a single ectopic focus in the ventricles. Determine whether the patient has a pulse. If no pulse is present, provide emergent basic and advanced life-support interventions, including defibrillation. If a pulse is present and the blood pressure is stable, the patient can be treated with intravenous amiodarone or lidocaine. Cardioversion is used as an emergency measure in patients who become hemodynamically unstable but continue to have a pulse. It also may be used in nonemergency situations, such as when a patient has asymptomatic VT.

The rhythm on the cardiac monitor is showing numerous pacemaker spikes, but no P waves or QRS complexes following the spikes. The nurse recognizes this as: a. normal pacemaker function. b. failure to capture. c. failure to pace. d. failure to sense.

ANS: B When the pacemaker generates an electrical impulse (pacer spike) and no depolarization is noted, it is described as a failure to capture. On the ECG, a pacer spike is noted, but it is not followed by a P wave (atrial pacemaker) or a QRS complex (ventricular pacemaker). This is not normal pacemaker function. Failure to pace or fire occurs when the pacemaker fails to initiate an electrical stimulus when it should fire. The problem is noted by absence of pacer spikes on the rhythm strip. When the pacemaker does not sense the patient's own cardiac rhythm and initiates an electrical impulse, it is called failure to sense. Failure to sense manifests as pacer spikes that fall too closely to the patient's own rhythm, earlier than the programmed rate.

The patient is admitted with a condition that requires cardiac rhythm monitoring. To apply the monitoring electrodes, the nurse must first a. apply a moist gel to the chest. b. make certain that the electrode gel is dry. c. avoid soaps to avoid skin irritation. d. clip chest hair if needed.

ANS: D Adequate skin preparation of electrode sites requires clipping the hair, cleansing the skin, and drying vigorously (moisture gels are not applied). Cleansing includes washing with soap and water, or alcohol, to remove skin debris and oils. Before application, the electrodes are checked to ensure that the gel is moist. It is difficult for electrodes to adhere to the chest in the presence of chest hair. Clipping, not shaving, is recommended since shaving may create small nicks that can become a portal for infection.

The nurse is assessing an older adult client with a cardiac dysrhythmia. Which finding would the nurse identify as contributing to this client's dysrhythmia? A) Drinks caffeinated coffee in the morning and for lunch. B) Does not smoke or ingest any alcohol. C) Plays golf three times a week and gardens daily. D) Takes antihypertensive medication as prescribed.

Answer: A Explanation: Aging affects the heart and the cardiac conduction system, increasing the incidence of dysrhythmias and conduction defects. Caffeine increases the risk of ectopic beats and rapid heart rates. Antihypertensive medications are not associated with cardiac dysrhythmias. Engaging in routine physical activity will not cause dysrhythmias or conduction defects. The client is a non-smoker and does not ingest alcohol, both of which would contribute to cardiac dysrhythmias.

An adult client is experiencing paroxysmal supraventricular tachycardia. Which nursing interventions are appropriate based on the data provided? Select all that apply. A) Massage the carotid arteries. B) Prepare for cardioversion. C) Begin anticoagulation therapy. D) Administer intravenous adenosine. E) Administer a beta blocker.

Answer: A, B, D, E Explanation: Management of paroxysmal supraventricular tachycardia includes carotid sinus massage, adenosine, beta blockers, and synchronized cardioversion. Anticoagulant therapy is not a part of the management for this dysrhythmia.

A client is receiving procainamide hydrochloride (Pronestyl) for treatment of a dysrhythmia. Which outcome indicates the client is adhering to the provided medication instruction? A) The client will monitor the pulse and not take the medication if the pulse is less than 60. B) The client will take the medication as directed, even when feeling well. C) The client will take the medication on an empty stomach. D) The client will take the medication with food.

Answer: B Explanation: It is very important for clients to understand that medication must be taken as directed, even if the client is feeling well. Procainamide hydrochloride (Pronestyl) can be taken on an empty stomach. The beta-adrenergic blocking drugs cause bradycardia, not Group 1A cardiac antiarrhythmic drugs like procainamide hydrochloride (Pronestyl). Procainamide hydrochloride (Pronestyl) can be taken with food.

A client admitted with a cardiac dysrhythmia reports being easily fatigued and frustrated with the inability to perform normal daily activities. Which nursing diagnosis should the nurse select to address this client's issue? A) Excess Fluid Volume B) Activity Intolerance C) Depression D) Situational Low Self-Esteem

Answer: B Explanation: The client is experiencing fatigue and frustration with the inability to perform normal daily activities. The nursing diagnosis to address this client's issue would be Activity Intolerance. There is no evidence that the client is experiencing excess fluid volume. The client may or may not be experiencing depression. The client may develop situational low self-esteem if the diagnosis of Activity Intolerance is not addressed.

A client with sepsis has a temperature of 40°Celsius. Which potentially life-threatening dysrhythmia is most likely to occur in this client? A) Bradyarrhythmia B) Tachyarrhythmia C) Wolff-Parkinson-White dysrhythmia D) Long QT dysrhythmia

Answer: B Explanation: This client is febrile and at risk for developing a tachyarrhythmia. Fever does not cause bradyarrhythmia. Wolff-Parkinson-White and long QT are both syndromes which are caused by genetic cardiac problems.

A nurse caring for a client in the in the intensive care unit (ICU) notes that the client is experiencing a ventricular tachycardia dysrhythmia. Which rhythm is classified as supraventricular? A) Sinus tachycardia B) Atrial flutter C) Junctional escape D) Torsades de Pointes

Answer: B Explanation: Torsades de Pointes is a type of ventricular tachycardia. Sinus tachycardia is sinus dysrhythmia, atrial flutter is a supraventricular dysrhythmia, and junctional escape is a junctional dysrhythmia.

During a blood pressure screening, an older adult client tells the nurse about chest fluttering while doing yard work. The client reports no other symptoms and the frequency is intermittent. Which conclusion by the nurse is the most appropriate based on the data provided? A) Exercise intolerance B) Nonspecific cardiac changes with aging C) Underlying illness that requires a medical evaluation D) Hypothyroidism

Answer: C Explanation: New-onset atrial fibrillation and other arrhythmias may signal the onset of a serious underlying illness that requires further medical evaluation. Chest fluttering can be a sign of hyperthyroidism, not hypothyroidism. These symptoms are not normal cardiac changes. Exercise intolerance would include shortness of breath, which the client does not report.

The nurse is planning care for a client admitted with a cardiac dysrhythmia. Which action would be the most appropriate for this client? A) Restrict fluids. B) Encourage bed rest. C) Monitor serum electrolyte levels. D) Instruct in a low-fat diet.

Answer: C Explanation: The nurse should monitor serum electrolyte levels because electrolyte imbalances affect cardiac depolarization and repolarization, and may cause dysrhythmias. More information is needed before determining whether the client needs to be on bed rest. There is no evidence to suggest the client needs to have fluids restricted. There is no evidence to suggest the client needs instruction on a low-fat diet.

A nurse working in the emergency department is participating in the resuscitation of a client experiencing sudden cardiac death. After 5 cycles of CPR, the nurse evaluates the client's cardiac rhythm as asystole. What is the next action by the nurse? A) Administer epinephrine. B) Immediately defibrillate the client. C) Assess the cardiac monitor electrodes. D) Assess the client's pulse.

Answer: D Explanation: According to AHA CPR guidelines, after 5 rounds of CPR, the nurse should assess the client's pulse. All other choices are incorrect actions by the nurse.

A client is scheduled for permanent pacemaker insertion. What instruction will this client need prior to discharge? A) Dizziness is to be expected. B) There are no special precautions. C) Wear a tight-fitting shirt to help hold the pacemaker in place. D) Use battery-powered equipment.

Answer: D Explanation: The client should be instructed to use electrical equipment with a grounded plug and avoid using adapters or extension cords. Battery-powered equipment should be used instead. There are special precautions for the client to be aware of with a permanent pacemaker. The client should wear loose-fitting clothing. Dizziness is not to be expected and should be reported to the healthcare provider.

ANS: A Atrial flutter arises from a single irritable focus in the atria. The atrial focus fires at an extremely rapid, regular rate, between 240 and 320 beats per minute. The P waves are called flutter waves and may have a sawtooth appearance. The ventricular response may be regular or irregular based on how many flutter waves are conducted through the AV node. Atrial flutter with RVR occurs when atrial impulses cause a ventricular response greater than 100 beats per minute. Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction.

Interpret the following rhythm: a. Atrial flutter with variable conduction b. Ventricular fibrillation c. Atrial fibrillation d. Atrial flutter with RVR (rapid ventricular response)

ANS: B Ventricular fibrillation (VF) is a chaotic rhythm characterized by a quivering of the ventricles, which results in total loss of cardiac output and pulse. VF is a life-threatening emergency, and the more immediate the treatment, the better the survival will be. VF produces a wavy baseline without a PQRST complex. Because a loose lead or electrical interference can produce a waveform similar to VF, it is always important to immediately assess the patient for pulse and consciousness. If no pulse is present, provide emergent basic and advanced life-support interventions, including defibrillation. IV medications can be used as part of advanced life support. Cardioversion is not warranted since the patient is pulseless. This rhythm is not benign and cannot be ignored.

The nurse notes the following rhythm on the heart monitor. The patient is unresponsive and not breathing. The nurse should a. treat with intravenous amiodarone or lidocaine. b. provide emergent basic and advanced life support. c. provide electrical cardioversion. d. ignore the rhythm because it is benign.

The normal width of the QRS complex is which of the following? (Select all that apply.) a. 0.06 to 0.10 seconds. b. 0.12 to 0.20 seconds. c. 1.5 to 2.5 small boxes. d. 3.0 to 5.0 small boxes. e. 0.04 seconds or greater.

ANS: A, C The waveform that initiates the QRS complex (whether it is a Q wave or an R wave) marks the beginning of the interval. The normal width of the QRS complex is 0.06 to 0.10 seconds. This width equals 1.5 to 2.5 small boxes. The normal PR interval is 0.12 to 0.20 seconds, three to five small boxes wide; not the QRS interval. A pathological Q wave has a width of 0.04 seconds and a depth that is greater than one fourth of the R wave amplitude; therefore, the QRS complex would be wider than that.

The possible P waveforms that are associated with junctional rhythms include which of the following? (Select all that apply.) a. No P wave b. Inverted P wave c. Shortened PR interval d. P wave after the QRS complex e. Normal P wave and PR interval

ANS: A, B, C, D Because of the location of the AV node—in the center of the heart—impulses generated may be conducted forward, backward, or both. With the potential of forward, backward, or bidirectional impulse conduction, three different P waveforms may be associated with junctional rhythms: When the AV node impulse moves forward, P waves may be absent because the impulse enters the ventricle first. The atria receives the wave of depolarization at the same time as the ventricles; thus, because of the larger muscle mass of the ventricles, there is no P wave. When the AV node impulse is conducted backward, the impulse enters the atria first. When depolarization occurs backward, an inverted P wave is created. Once the atria have been depolarized, the impulse moves down the bundle of His and depolarizes both ventricles normally. A short PR interval (<0.12 second) is noted. When the impulse is conducted both forward and backward, P waves may be present after the QRS complex.

Sinus bradycardia is a symptom of which of the following? (Select all that apply.) a. Calcium channel blocker medication b. Beta blocker medication c. Athletic conditioning d. Hypothermia e. Hyperthyroidism

ANS: A, B, C, D Vasovagal response; medications such as digoxin or AV nodal blocking agents, including calcium channel blockers and beta blockers; myocardial infarction; normal physiological variant in the athlete; disease of the sinus node; increased intracranial pressure; hypoxemia; and hypothermia may cause sinus bradycardia. Hyperthyroidism is a cause of sinus tachycardia.

Which of the following are common causes of sinus tachycardia? (Select all that apply.) a. Hyperthyroidism b. Hypovolemia c. Hypothyroidism d. Heart Failure e. Sleep

ANS: A, B, D Common causes of sinus tachycardia include hyperthyroidism, hypovolemia, heart failure, anemia, exercise, use of stimulants, fever, and sympathetic response to fear or pain and anxiety. Hypothyroidism and sleep tend to slow the heart rate.

The nurse is reading the cardiac monitor and notes that the patient's heart rhythm is extremely irregular and that there are no discernible P waves. The ventricular rate is 90 beats per minute, and the patient is hemodynamically stable. The nurse realizes that the patient's rhythm is a. atrial fibrillation. b. atrial flutter. c. atrial flutter with rapid ventricular response. d. junctional escape rhythm.

ANS: A Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. No discernible P waves can be identified, resulting in a wavy baseline and an extremely irregular ventricular response. Atrial flutter arises from a single irritable focus in the atria. The atrial focus fires at an extremely rapid, regular rate, between 240 and 320 beats per minute. The P waves are called flutter waves and may have a sawtooth appearance. Atrial flutter with rapid ventricular response occurs when atrial impulses cause a ventricular response greater than 100 beats per minute. A junctional escape rhythm is a ventricular rate between 40 and 60 beats per minute with a regular rhythm. P waves may be absent, inverted, or follow the QRS complex. QRS complex is normal.

The nurse notices sinus bradycardia on the patient's cardiac monitor. The nurse should a. give atropine to increase heart rate. b. begin transcutaneous pacing of the patient. c. start a dopamine infusion to stimulate heart function. d. assess for hemodynamic instability.

ANS: D Sinus bradycardia may be a normal heart rhythm for some individuals such as athletes, or it may occur during sleep. Assess for hemodynamic instability related to the bradycardia. If the patient is symptomatic, interventions include administration of atropine. If atropine is not effective in increasing heart rate, then transcutaneous pacing, dopamine infusion, or epinephrine infusion may be administered. Atropine is avoided for treatment of bradycardia associated with hypothermia.

The nurse is talking with the patient when the monitor alarms and shows a wavy baseline without a PQRST complex. The nurse should a. defibrillate the patient immediately. b. initiate basic life support. c. initiate advanced life support. d. assess the patient and the electrical leads.

ANS: D Ventricular fibrillation (VF) is a chaotic rhythm characterized by a quivering of the ventricles, which results in total loss of cardiac output and pulse. VF is a life-threatening emergency, and the more immediate the treatment is, the better the survival will be. VF produces a wavy baseline without a PQRST complex. Because a loose lead or electrical interference can produce a waveform similar to VF, it is always important to immediately assess the patient for pulse and consciousness.

ANS: B Normal sinus rhythm (NSR) reflects normal conduction of the sinus impulse through the atria and ventricles. Atrial and ventricular rates are the same and range from 60 to 100 beats per minute. Rhythm is regular or essentially regular. PR interval is 0.12 to 0.20 seconds. QRS interval is 0.06 to 0.10 seconds. P and QRS waves are consistent in shape. Sinus tachycardia results when the SA node fires faster than 100 beats per minute. Bradycardia is defined as a heart rate less than 60 beats per minute. Sinus arrhythmia is a cyclical change in heart rate that is associated with respiration. The heart rate increases slightly during inspiration and slows slightly during exhalation because of changes in vagal tone.

Interpret the following rhythm: a. Normal sinus rhythm b. Sinus bradycardia c. Sinus tachycardia d. Sinus arrhythmia

The patient has a pacemaker with one pacing spike seen on the ECG before every QRS complex. There is no change in the pacemaker rhythm over time, with rest or with activity. The nurse realizes the patient has what type of pacemaker? 1. asynchronous pacing 2. demand pacing 3. dual-chamber pacing 4. atrial single-chamber pacing

Correct Answer: 1 Rationale 1: Asynchronous pacing delivers a pacing stimulus at a set rate regardless of intrinsic cardiac activity. Rationale 2: A demand pacemaker spike varies with the heart rate. Rationale 3: A dual-chamber pacer normally produces two pacing spikes, one before the P wave and one before the QRS. Rationale 4: An atrial pacer would produce a spike, normally with a P wave that follows it prior to the QRS. Global Rationale: Asynchronous pacing delivers a pacing stimulus at a set rate regardless of intrinsic cardiac activity. A demand pacemaker spike varies with the heart rate. A dual-chamber pacer normally produces two pacing spikes, one before the P wave and one before the QRS. An atrial pacer would produce a spike, normally with a P wave that follows it prior to the QRS.

ANS: C Normal sinus rhythm (NSR) reflects normal conduction of the sinus impulse through the atria and ventricles. Atrial and ventricular rates are the same and range from 60 to 100 beats per minute. Rhythm is regular or essentially regular. PR interval is 0.12 to 0.20 seconds. QRS interval is 0.06 to 0.10 seconds. P and QRS waves are consistent in shape. Sinus tachycardia results when the SA node fires faster than 100 beats per minute. Bradycardia is defined as a heart rate less than 60 beats per minute. Sinus arrhythmia is a cyclical change in heart rate that is associated with respiration. The heart rate slightly increases during inspiration and slightly slows during exhalation because of changes in vagal tone.

Interpret the following rhythm: a. Normal sinus rhythm b. Sinus bradycardia c. Sinus tachycardia d. Sinus arrhythmia

A client is prescribed a calcium channel blocker for control of hypertension is now prescribed a beta blocker to control a fast ventricular rate. What should the nurse include in instructions regarding the medications? 1. Eat a high-fiber, low-carbohydrate diet. 2. Do not take this medication with grapefruit juice. 3. Maintain a daily exercise regimen. 4. Report irregular heart rate or shortness of breath to the health care provider.

Correct Answer: 4 Rationale 1: The diet should be low in salt and fat. Rationale 2: There is no contraindication to taking these classifications of medications with grapefruit. Rationale 3: Everyone should maintain an exercise regimen. This is not specific to the classification of medication given. Rationale 4: Because concurrent use of a calcium channel blocker and a beta-adrenergic blocker can cause partial or complete heart block, palpitations or dyspnea should be reported immediately. The nurse should give instructions in terms the client can understand. Global Rationale: Because concurrent use of a calcium channel blocker and a beta-adrenergic blocker can cause partial or complete heart block, palpitations or dyspnea should be reported immediately. The nurse should give instructions in terms the client can understand. The diet should be low in salt and fat. There is no contraindication to taking these classifications of medications with grapefruit. Everyone should maintain an exercise regimen. This is not specific to the classification of medication given.

A client in the emergency department complains of chest pain, diaphoresis, shortness of breath, lightheadedness, and dizziness. The cardiac monitor displays ventricular tachycardia at 180 beats per minute. What is the nurse's most immediate concern for this client? 1. The client may be experiencing a posterior myocardial infarction. 2. The client may suffer a cerebral vascular accident. 3. The client is at risk for development of a pulmonary embolism. 4. The client is at risk for cardiac death.

Correct Answer: 4 Rationale 1: While a myocardial infarction may occur, this is not the most immediate concern. Rationale 2: A cerebral vascular accident may occur, but this is not the most immediate concern. Rationale 3: Prevention of an embolism is not first priority. Rationale 4: The most vital concern is deterioration into cardiac arrest. If not treated quickly, the client will die due to lack of circulation of oxygen. Global Rationale: The most vital concern is deterioration into cardiac arrest. If not treated quickly, the client will die due to lack of circulation of oxygen. While a myocardial infarction and cerebral vascular accident may occur, these are not the most immediate concern. Prevention of an embolism is not first priority.

A client is admitted with the medical diagnosis of sick sinus syndrome. The nurse expects that this client's apical pulse will be less than _____ beats per minute. Standard Text: Record answer rounded to the nearest whole number.

Correct Answer: 40 Rationale: In sick sinus syndrome, the SA node fails to generate or transmit sufficient electrical impulses. A client with this diagnosis experiences severe bradycardia with a rate lower than 40 beats per minute. Global Rationale: In sick sinus syndrome, the SA node fails to generate or transmit sufficient electrical impulses. A client with this diagnosis experiences severe bradycardia with a rate lower than 40 beats per minute.

ANS: A Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. The AV node is bombarded with hundreds of atrial impulses and conducts these impulses in an unpredictable manner to the ventricles. The atrial rate may be as high 700 and no discernible P waves can be identified, resulting in a wavy baseline and an extremely irregular ventricular response. Atrial flutter arises from a single irritable focus in the atria. The atrial focus fires at an extremely rapid, regular rate, between 240 and 320 beats per minute. The P waves are called flutter waves and may have a sawtooth appearance. The ventricular response may be regular or irregular based on how many flutter waves are conducted through the AV node. Atrial flutter with RVR occurs when atrial impulses cause a ventricular response greater than 100 beats per minute. A junctional escape rhythm is a ventricular rate between 40 and 60 beats per minute with a regular rhythm. P waves may be absent, inverted, or follow the QRS complex. If a P wave is present before the QRS complex, the PR interval is shortened to less than 0.12 milliseconds. QRS complex is normal.

Interpret the following rhythm: a. Atrial fibrillation b. Atrial flutter c. Atrial flutter with RVR d. Junctional escape rhythm

ANS: A Pacemakers may be used to stimulate the atrium, ventricle, or both chambers (dual-chamber pacemakers). Atrial pacing is used to mimic normal conduction and to produce atrial contraction, thus providing atrial kick. This is the case in the scenario provided. Ventricular pacing stimulates ventricular depolarization and is commonly used in emergency situations or when pacing is required infrequently. Dual-chamber pacing allows for stimulation of both atria and ventricles as needed to synchronize the chambers and mimic the normal cardiac cycle. However, with this patient, ventricular and AV function are normal. Transcutaneous pacing is delivered through the skin via external electrode pads connected to an external pacemaker.

Interpret the following rhythm: a. Atrial pacing b. Ventricular pacing c. Dual-chamber pacing d. Transcutaneous pacing

Correct Answer: 1 Rationale 1: Ventricular fibrillation is too rapid to count and is grossly irregular; P:QRS shows no identifiable P waves; the PR interval is absent, and the QRS interval is bizarre and varies in shape and direction. It is important to identify this rhythm since it is a medical emergency and is known as cardiac arrest since the heart is not pumping. Death will follow if this situation is not resolved within four minutes. Rationale 2: This rhythm is not atrial flutter. Rationale 3: This rhythm is not sinus tachycardia. Rationale 4: This rhythm is not ventricular tachycardia. Global Rationale: Ventricular fibrillation is too rapid to count and is grossly irregular; P:QRS shows no identifiable P waves; the PR interval is absent, and the QRS interval is bizarre and varies in shape and direction. It is important to identify this rhythm since it is a medical emergency and is known as cardiac arrest since the heart is not pumping. Death will follow if this situation is not resolved within four minutes. This rhythm is not atrial flutter, sinus tachycardia, or ventricular tachycardia.

The nurse sees this rhythm on a patient's cardiac monitor. For which rhythm should the nurse begin care? 1. ventricular fibrillation 2. atrial flutter 3. sinus tachycardia 4. ventricular tachycardia

ANS: D Ventricular tachycardia (VT) is a rapid, life-threatening dysrhythmia originating from a single ectopic focus in the ventricles. It is characterized by at least three PVCs in a row. VT occurs at a rate greater than 100 beats per minute, but the rate is usually around 150 beats per minute and may be up to 250 beats per minute. Depolarization of the ventricles is abnormal and produces a widened QRS complex. The patient may or may not have a pulse. Determine whether the patient has a pulse. If no pulse is present, provide emergent basic and advanced life-support interventions, including defibrillation. If a pulse is present and the blood pressure is stable, the patient can be treated with intravenous amiodarone or lidocaine.

The patient is alert and talking when the nurse notices the following rhythm. The patient's blood pressure is 90/44 mm Hg. The nurse should a. defibrillate immediately. b. begin basic life support. c. begin advanced life support. d. treat with intravenous amiodarone or lidocaine.

The patient has a permanent pacemaker inserted. The provider has set the pacemaker to the demand mode at a rate of 60 beats per minute. The nurse realizes that a. the pacemaker will pace only if the patient's intrinsic heart rate is less than 60 beats per minute. b. the demand mode often competes with the patient's own rhythm. c. the demand mode places the patient at risk for the R-on-T phenomenon. d. the fixed-rate mode is safer and is the mode of choice.

ANS: A Pacemakers can be operated in a demand mode or a fixed-rate (asynchronous) mode. The demand mode paces the heart when no intrinsic or native beat is sensed. For example, if the rate control is set at 60 beats per minute, the pacemaker will only pace if the patient's heart rate drops to less than 60. The fixed-rate mode paces the heart at a set rate, independent of any activity the patient's heart generates. The fixed-rate mode may compete with the patient's own rhythm and deliver an impulse on the T wave (R-on-T phenomenon), with the potential for producing ventricular tachycardia or fibrillation. The demand mode is safer and is the mode of choice.

The patient is in chronic junctional escape rhythm with no atrial activity noted. Studies have demonstrated normal AV node function. This patient may be a candidate for which type of pacing? a. Atrial pacing b. Ventricular pacing c. Dual-chamber pacing d. Transcutaneous pacing

ANS: A Pacemakers may be used to stimulate the atrium, ventricle, or both chambers (dual-chamber pacemakers). Atrial pacing is used to mimic normal conduction and to produce atrial contraction, thus providing atrial kick. This is the case in the scenario provided. Ventricular pacing stimulates ventricular depolarization and is commonly used in emergency situations or when pacing is required infrequently. Dual-chamber pacing allows for stimulation of both atria and ventricles as needed to synchronize the chambers and mimic the normal cardiac cycle. However, with this patient, ventricular and AV function are normal.

Which of the following is true about a patient diagnosed with sinus arrhythmia? a. The heart rate varies, dependent on vagal tone and respiratory pattern. b. Immediate treatment is essential to prevent death. c. Sinus arrhythmia is not well tolerated by most patients. d. PR and QRS interval measurements are prolonged.

ANS: A Sinus arrhythmia is a cyclical change in heart rate that is associated with respiration. The heart rate increases slightly during inspiration and slows slightly during exhalation because of changes in vagal tone. The ECG tracing demonstrates an alternating pattern of faster and slower heart rate that changes with the respiratory cycle. Interval measurements are normal. This rhythm is tolerated well, and no treatment is required. The PR and QRS intervals are normal.

The nurse is caring for a patient who is on a cardiac monitor. The nurse realizes that the sinus node is the pacemaker of the heart because it is a. the fastest pacemaker cell in the heart. b. the only pacemaker cell in the heart. c. the only cell that does not affect the cardiac cycle. d. located in the left side of the heart.

ANS: A The cardiac cycle begins with an impulse that is generated from a small concentrated area of pacemaker cells high in the right atria called the sinoatrial node (sinus node or SA node). The SA node has the fastest rate of discharge and thus is the dominant pacemaker of the heart. The AV node has pacemaker properties and can discharge an impulse if the SA node fails. The ventricles have pacemaker capabilities if the sinus node or the AV node ceases to generate impulses.

The patient has an irregular heart rhythm. To determine an accurate heart rate, the nurse would first a. identify the markers on the ECG paper that indicate a 6-second strip. b. count the number of small boxes between two consecutive P waves. c. count the number of small boxes between two consecutive QRS complexes. d. divides the number of complexes in a 6-second strip by 10.

ANS: A The optimal method of determining a heart rate from an ECG strip when the patient has an irregular heart rate is to count the number of P waves or QRS waves within a 6-second strip to obtain both atrial and ventricular heart rates per minute. In order to do this accurately, the nurse first much identify the markers on the ECG paper that indicate a 6-second strip. The other methods are not as accurate with an irregular heart rate.

The patient is in third-degree heart block (complete heart block) and is symptomatic. The treatment for this patient is which of the following? (Select all that apply.) a. Transcutaneous pacemaker b. Atropine IV c. Temporary transvenous pacemaker d. Permanent pacemaker e. Amiodarone IV

ANS: A, C, D Treatments include transcutaneous or transvenous pacing and implanting a permanent pacemaker. Atropine reduces vagal tone, but that is not a cause of complete heart block and will produce more P waves, but the P waves will still not be associated with the QRS complexes. It is important to note that the only treatment is pacing. Amiodarone IV is used to suppress ventricular dysrhythmia and is not used to treat third-degree heart block.

The nurse is caring for a patient who has atrial fibrillation. Sequelae that place the patient at greater risk for mortality/morbidity include which of the following? (Select all that apply.) a. Stroke b. Ashman beats c. Pulmonary emboli d. Prolonged PR interval e. Decreased cardiac output

ANS: A, C, E One complication of atrial fibrillation is thromboembolism. The blood that collects in the atria is agitated by fibrillation, and normal clotting is accelerated. Small thrombi, called mural thrombi, begin to form along the walls of the atria. These clots may dislodge, resulting in pulmonary embolism or stroke. The ineffectual contraction of the atria results in loss of "atrial kick." If too many impulses conduct to the ventricles, atrial fibrillation with rapid ventricular response may result and compromise cardiac output. Ashman beats are not clinically significant. No recognizable or discernible P waves are present; therefore, PR interval is absent.

The patient is admitted with a fever and rapid heart rate. The patient's temperature is 103F (39.4C). The nurse places the patient on a cardiac monitor and finds the patient's atrial and ventricular rates are above 105 beats per minute. P waves are clearly seen and appear normal in configuration. QRS complexes are normal in appearance and 0.08 seconds wide. The rhythm is regular, and blood pressure is normal. The nurse should focus on providing: a. medications to lower heart rate. b. treatment to lower temperature. c. treatment to lower cardiac output. d. treatment to reduce heart rate.

ANS: B Sinus tachycardia results when the SA node fires faster than 100 beats per minute. All other components of the ECG are normal. Sinus tachycardia is a normal response to stimulation of the sympathetic nervous system. Sinus tachycardia is also a normal finding in children younger than 6 years. The fast heart rhythm may cause a decrease in cardiac output because of the shorter filling time for the ventricles. Lowering cardiac output further may complicate the situation. The dysrhythmia itself is not treated, but the cause is identified and treated appropriately. For example, if the patient has a fever or is in pain, the fever (and infection) or pain is treated appropriately.

One of the functions of the atrioventricular (AV) node is to a. pace the heart if the ventricles fail. b. slow the impulse arriving from the SA node. c. send the impulse to the SA node. d. allow for ventricular filling during systole.

ANS: B The impulse from the SA node quickly reaches the atrioventricular (AV) node located in the area called the AV junction, between the atria and the ventricles. Here the impulse is slowed to allow time for ventricular filling during relaxation or ventricular diastole. The AV node has pacemaker properties and can discharge an impulse if the SA node (not the ventricle) fails. The electrical impulse is then rapidly conducted through the bundle of His to the ventricles (not the SA node) via the left and right bundle branches.

The patient's heart rate is 70 beats per minute, but the P waves come after the QRS complex. The nurse correctly determines that the patient's heart rhythm is a. a normal junctional rhythm. b. an accelerated junctional rhythm. c. a junctional tachycardia. d. atrial fibrillation.

ANS: B The normal intrinsic rate for the AV node and junctional tissue is 40 to 60 beats per minute, but rates can accelerate. An accelerated junctional rhythm has a rate between 60 and 100 beats per minute, and the rate for junctional tachycardia is greater than 100 beats per minute. If P wave precedes QRS, it is inverted or upside down; the P wave may not be visible, or it may follow the QRS. If a P wave is present before the QRS, the PR interval is shortened less than 0.12 milliseconds. Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. The AV node is bombarded with hundreds of atrial impulses and conducts these impulses in an unpredictable manner to the ventricles.

The nurse is calculating the rate for a regular rhythm. There are 20 small boxes between each P wave and 20 small boxes between each R wave. What is the ventricular rate? a. 50 beats/min b. 75 beats/min c. 85 beats/min d. 100 beats/min

ANS: B The rule of 1500 is used to calculate the exact rate of a regular rhythm. The number of small boxes between the highest points of two consecutive R waves is counted, and that number of small boxes is divided into 1500 to determine the ventricular rate. 1500/20 = 75 beats/min. This method is accurate only if the rhythm is regular.

The normal rate for the SA node when the patient is at rest is a. 40 to 60 beats per minute. b. 60 to 100 beats per minute. c. 20 to 40 beats per minute. d. more than100 beats per minute.

ANS: B The sinus node reaches threshold at a rate of 60 to 100 times per minute. Because this is the fastest pacemaker in the heart, the SA node is the dominant pacemaker of the heart. The AV node has an inherent rate of 40 to 60 beats per minute and the His-Purkinje system can fire at a rate of 20 to 40 beats per minute. Sinus tachycardia results when the SA node fires faster than 100 beats per minute.

The patient is admitted with sinus pauses causing periods of loss of consciousness. The patient is asymptomatic, awake and alert, but fatigued. He answers questions appropriately. When admitting this patient, the nurse should first a. prepare the patient for temporary pacemaker insertion. b. prepare the patient for permanent pacemaker insertion. c. assess the patient's medication profile. d. apply transcutaneous pacemaker paddles.

ANS: C AV nodal blocking medications (such as beta blockers, calcium channel blockers, and digoxin) and increased vagal tone may cause sinus exit block. Causes are explored, and prescribed medications may need to be adjusted or discontinued. If patients are symptomatic, significant numbers of pauses may require treatment, including temporary (including transcutaneous) and permanent implantation of a pacemaker.

The patient is asymptomatic but is diagnosed with second-degree heart block Mobitz I. The patient is on digitalis medication at home. The nurse should expect that a. the patient has had an anterior wall myocardial infarction. b. the physician will order the digitalis to be continued in the hospital. c. a digitalis level would be ordered upon admission. d. the patient will require a transcutaneous pacemaker.

ANS: C Digitalis toxicity is a major cause of this rhythm, and further digitalis doses should not be given until a digitalis level is obtained. Other causes of Mobitz I include AV nodal blocking drugs, acute inferior wall myocardial infarction or right ventricular infarction, ischemic heart disease, and excess vagal response. This type of block is usually well tolerated, and no treatment is indicated unless the dropped beats occur frequently.

The patient has a permanent pacemaker in place with a demand rate set at 60 beats/min. The cardiac monitor is showing a heart rate of 44 beats/min with no pacemaker spikes. The nurse recognizes this as: a. normal pacemaker function. b. failure to capture. c. failure to pace. d. failure to sense.

ANS: C Failure to pace or fire occurs when the pacemaker fails to initiate an electrical stimulus when it should fire. The problem is noted by absence of pacer spikes on the rhythm strip. Causes of failure to pace include battery or pulse generator failure, fracture or displacement of a pacemaker wire, or loose connections. This is not normal pacemaker function. When the pacemaker generates an electrical impulse (pacer spike) and no depolarization is noted, it is described as a failure to capture. On the ECG, a pacer spike is noted, but it is not followed by a P wave (atrial pacemaker) or a QRS complex (ventricular pacemaker). When the pacemaker does not sense the patient's own cardiac rhythm and initiates an electrical impulse, it is called failure to sense. Failure to sense manifests as pacer spikes that fall too closely to the patient's own rhythm, earlier than the programmed rate.

The nurse notices that the patient has a first-degree AV block. Everything else about the rhythm is normal. The nurse should a. prepare to place the patient on a transcutaneous pacemaker. b. give the patient atropine to shorten the PR interval. c. monitor the rhythm and patient's condition. d. give the patient an antiarrhythmic medication.

ANS: C First-degree AV block is a common dysrhythmia in the elderly and in patients with cardiac disease. As the normal conduction pathway ages or becomes diseased, impulse conduction becomes slower than normal. It is well tolerated. No treatment is required. Continue to monitor the patient and the rhythm.

The patient is scheduled to have a permanent pacemaker implanted. The patient asks the nurse, "How long will the battery in this thing last?" The nurse should answer, a. "Life expectancy is about 1 year. Then it will need to be replaced." b. "Pacemaker batteries can last up to 25 years with constant use." c. "Battery life varies depending on usage, but it can last up to 10 years." d. "Pacemakers are used to treat temporary problems, so the batteries don't last long."

ANS: C Implanted permanent pacemakers are used to treat chronic conditions. These devices have a battery life of up to 10 years, which varies based on the manufacturer's recommendations and the usage of the device.

The nurse caring for patients on cardiac monitors assesses the patient with a prolonged QT interval for a. electrolyte disturbances such as hypokalemia. b. symptomatic bradycardias. c. the development of lethal dysrhythmias. d. difficulty maintaining the blood pressure.

ANS: C The QT interval is measured from the beginning of the QRS complex to the end of the T wave. This interval measures the total time taken for ventricular depolarization and repolarization. Abnormal prolongation of the QT interval increases vulnerability to lethal dysrhythmias, such as ventricular tachycardia and fibrillation. The nurse monitors the patient for the development of these rhythms and is prepared to intervene should they occur. A prolonged QT is not associated with bradycardias, hypokalemia, or blood pressure irregularities.

The nurse understands that in a third-degree AV block a. every P wave is conducted to the ventricles. b. some P waves are conducted to the ventricles. c. none of the P waves are conducted to the ventricles. d. the PR interval is prolonged.

ANS: C Third-degree block is often called complete heart block because no atrial impulses are conducted through the AV node to the ventricles. Normally every P wave is conducted to the ventricles. If some of the P waves are conducted but others are not, further assessment is needed to determine the type of block present. A prolonged PR interval is a first-degree AV block, and is well tolerated and requires no treatment.

The nurse caring for patients with cardiac monitoring understands that when an electrical signal is aimed directly at the positive electrode, the inflection will be: a. negative. b. upside down. c. upright. d. equally positive and negative.

ANS: C When an electrical signal is aimed directly at the positive electrode, an upright inflection is visualized. If the impulse is going away from the positive electrode, a negative deflection is seen; and if the signal is perpendicular to the imaginary line between the positive and negative poles of the lead, the tracing is equiphasic, with equally positive and negative deflection.

The patient's heart rate is 165 beats per minute. The cardiac monitor shows a rapid rate with narrow QRS complexes. The P waves cannot be seen, but the rhythm is regular. The patient's blood pressure has dropped from 124/62 mm Hg to 78/30 mm Hg. The patient's skin is cold and diaphoretic, and the patient is complaining of nausea. The nurse prepares the patient for a. administration of beta blockers. b. administration of atropine. c. transcutaneous pacemaker insertion. d. emergent cardioversion.

ANS: D If an abnormal P wave cannot be visualized on the ECG but the QRS complex is narrow, the term supraventricular tachycardia (SVT) is often used. This is a generic term that describes any tachycardia that is not ventricular in origin; it is also used when the source above the ventricles cannot be identified, usually because the rate is too fast. Treatment is directed at assessing the patient's tolerance of the tachycardia. If the rate is higher than 150 beats per minute and the patient is symptomatic, emergent cardioversion is considered. Cardioversion is the delivery of a synchronized electrical shock to the heart by an external defibrillator. Beta blockers are a possibility if the patient is not symptomatic. Atropine is used in the treatment of bradycardia. If atropine is not effective in increasing heart rate, then transcutaneous pacing is implemented.

A client presents to the emergency department (ED) with dyspnea, diaphoresis, and lightheadedness. The cardiac monitor reveals paroxysmal supraventricular tachycardia (SVT). Which class of antiarrhythmic drug does the nurse anticipate will be administered? 1. A calcium channel blocker 2. A class IC drug 3. A class IB drug 4. A class IA drug

Correct Answer: 1 Rationale 1: Calcium channel blockers are class IV antiarrhythmic drugs and are administered to treat SVT. Rationale 2: Class IC drugs are used for severe ventricular dysrhythmias. Rationale 3: Class IB drugs are used for severe ventricular dysrhythmias. Rationale 4: Class IA drugs are given for atrial fibrillation, premature atrial contractions, premature ventricular contractions, and tachycardia. Global Rationale: Calcium channel blockers are class IV antiarrhythmic drugs and are administered to treat SVT. Class IC and Class IB drugs are used for severe ventricular dysrhythmias. Class IA drugs are given for atrial fibrillation, premature atrial contractions, premature ventricular contractions, and tachycardia.

A patient received an implantable cardioverter-defibrillator (ICD). The nurse includes what instruction during discharge teaching for this patient? 1. "If a family member is in direct contact with you when the ICD discharges, he or she may experience a shock or tingling sensation." 2. "You can activate the ICD whenever you feel a change in your heart rhythm." 3. "The batteries of the ICD won't need to be replaced if the ICD never shocks the heart." 4. "There should be no discomfort if the ICD discharges, and you probably won't notice it."

Correct Answer: 1 Rationale 1: Family members may receive a shock or tingling sensation when in direct contact with an individual when their ICD discharges. Rationale 2: The ICD is programmed to automatically activate when detecting a potentially lethal cardiac rhythm and cannot be activated by the patient. Rationale 3: Batteries must be surgically replaced every five years or following manufacturer's instructions. Rationale 4: Some patients experience significant discomfort with ICD discharge. Global Rationale: Family members may receive a shock or tingling sensation when in direct contact with an individual when their ICD discharges. The ICD is programmed to automatically activate when detecting a potentially lethal cardiac rhythm and cannot be activated by the patient. Batteries must be surgically replaced every five years or following manufacturer's instructions. Some patients experience significant discomfort with ICD discharge.

Which statement would the nursing supervisor evaluate as indicating that a new cardiac nurse understands the fluxes associated with cardiac action potentials? 1. "Phase 4 is the time in which the cells rest." 2. "Depolarization occurs during phase 1." 3. "The inside of the plasma membrane becomes negative during phase 1." 4. "Repolarization occurs during phase 4."

Correct Answer: 1 Rationale 1: In phase 4, the action potential has not yet occurred and the cell is resting. Rationale 2: Depolarization occurs during phase 0. Rationale 3: The inside of the plasma membrane becomes positive during phase 1. Rationale 4: Repolarization is a phase 3 phenomenon. Global Rationale: In phase 4, the action potential has not yet occurred and the cell is resting. Depolarization occurs during phase 0. The inside of the plasma membrane becomes positive during phase 1. Repolarization is a phase 3 phenomenon.

What is the priority nursing intervention for a patient with a junctional escape rhythm? 1. Assess the patient for symptoms associated with this rhythm. 2. Contact the physician immediately for emergency orders. 3. Eliminate caffeine from the diet. 4. Prepare for a pacemaker insertion.

Correct Answer: 1 Rationale 1: Junctional escape rhythms may be monitored if the patient is not symptomatic. It is most important to assess the patient to see how they are affected by the rhythm. Rationale 2: Calling the physician to report the rhythm may be appropriate if the patient is symptomatic. Rationale 3: Eliminating caffeine is not an appropriate action for this patient with a junctional escape rhythm. No indication of symptoms relating to the rhythm was given. Rationale 4: Preparing for a pacemaker insertion is not an appropriate action for this patient with a junctional escape rhythm. No indication of symptoms relating to the rhythm was given. Global Rationale: Junctional escape rhythms may be monitored if the patient is not symptomatic. It is most important to assess the patient to see how they are affected by the rhythm. Calling the physician to report the rhythm may be appropriate if the patient is symptomatic. Eliminating caffeine or preparing for a pacemaker insertion is not an appropriate action for this patient with a junctional escape rhythm. No indication of symptoms relating to the rhythm was given.

A client is prescribed dofetilide (Tikosyn) for conversion of atrial fibrillation. The nurse plans to monitor for which adverse effect? 1. Widening of the QT interval 2. Inverted T waves 3. Widening of the PR interval 4. Widening of the QRS complex

Correct Answer: 1 Rationale 1: Like other potassium channel blockers, dofetilide prolongs the refractory period and action potential duration, thus increasing the QT interval. Rationale 2: T waves are not affected. Rationale 3: Dofetilide has no effect on the PR interval. Rationale 4: Dofetilide does not widen the QRS. Global Rationale: Like other potassium channel blockers, dofetilide prolongs the refractory period and action potential duration, thus increasing the QT interval. Dofetilide has no effect on the T waves or PR interval andit does not widen the QRS.

The nurse in a heart failure clinic explains the effect of cardiac dysrhythmia on the body to a group of clients. What is the most important information to include in this teaching? 1. "Cardiac rhythm disturbances cause the amount of blood pumped out of your heart to decrease." 2. "Most cardiac rhythm disturbances do not affect the body at all." 3. "The biggest problem with most cardiac rhythm disturbances is that they cause nervousness and irritability." 4. "Cardiac rhythm disturbances often cause gastrointestinal upset."

Correct Answer: 1 Rationale 1: One of the biggest results of cardiac rhythm disturbance is decreased cardiac output. Rationale 2: Any disturbance of rhythm has some effect in the body. The effects may be minor or major. Rationale 3: Clients with cardiac rhythm disturbances may experience nervousness or irritability, but this is not the major effect or concern. Rationale 4: Some cardiac rhythm disturbances do cause gastrointestinal upset, but this is not the major effect or concern. Global Rationale: One of the biggest results of cardiac rhythm disturbance is decreased cardiac output. Any disturbance of rhythm has some effect in the body. The effects may be minor or major. Clients with cardiac rhythm disturbances may experience nervousness or irritability, but this is not the major effect or concern. Some cardiac rhythm disturbances do cause gastrointestinal upset, but this is not the major effect or concern.

The nurse is caring for a patient with premature ventricular contractions (PVCs). What should the nurse keep in mind about this heart rhythm? 1. PVCs are insignificant in people with no history of heart disease. 2. PVCs typically have no pattern. 3. The frequency of PVCs is not associated with specific events. 4. Their incidence and significance has no relevance to the patient having had a myocardial infarction

Correct Answer: 1 Rationale 1: PVCs often have no significance in people without history of heart disease. Rationale 2: PVCs may be isolated or occur in specific patterns. Rationale 3: PVCs may be triggered by anxiety or stress; tobacco, alcohol or caffeine use; hypoxia, acidosis, and electrolyte imbalances; sympathomimetic drugs; and coronary heart disease. Rationale 4: PVCs may be associated with an increased risk for lethal dysrhythmias and their incidence and significance is greatest after myocardial infarction. Global Rationale: PVCs often have no significance in people without history of heart disease. PVCs may be isolated or occur in specific patterns. They may be triggered by anxiety or stress; tobacco, alcohol or caffeine use; hypoxia, acidosis, and electrolyte imbalances; sympathomimetic drugs; and coronary heart disease. They may be associated with an increased risk for lethal dysrhythmias and their incidence and significance is greatest after myocardial infarction.

A client is started on sotalol (Betapace) for conversion of atrial fibrillation. Which finding requires immediate nursing action? 1. A widening of the QRS complex 2. Complaints of a "flutter" feeling in the chest 3. Complaints of headache 4. Increased blood glucose level

Correct Answer: 1 Rationale 1: Sotalol delays repolarization and prolongs the refractory period, thus widening the QT interval. Widening of the QRS complex can be a precursor to ventricular tachycardia. The health care provider should be alerted immediately, and the medication held. Rationale 2: Complaints of a "flutter" feeling in the chest are characteristic of atrial fibrillation, for which the client is receiving treatment. Rationale 3: There is no indication that treatment with sotalol induces headache as an adverse effect. Rationale 4: There is no evidence that sotalol increases blood glucose levels. Global Rationale: Sotalol delays repolarization and prolongs the refractory period, thus widening the QT interval. Widening of the QRS complex can be a precursor to ventricular tachycardia. The health care provider should be alerted immediately, and the medication held. Complaints of a "flutter" feeling in the chest are characteristic of atrial fibrillation, for which the client is receiving treatment. There is no indication that treatment with sotalol induces headache or increased blood glucose levels as an adverse effect.

A nurse is performing cardiopulmonary resuscitation (CPR) on a patient who is in cardiac arrest. An automatic external defibrillator (AED) is available. What activity will allow the nurse to assess the patient's cardiac rhythm? 1. Apply adhesive patch electrodes to the chest and move away from the patient. 2. Apply standard electrocardiographic monitoring leads to the patient and observe the rhythm. 3. Hold the defibrillator paddles directly against the patient's chest. 4. Connect electrocardiographic electrodes to a telephone monitoring device and wait until the rhythm is analyzed.

Correct Answer: 1 Rationale 1: The nurse applies adhesive patch electrodes to the patient's chest in the usual defibrillator positions, stops CPR, and orders everyone near the patient to move away and not touch the patient. The defibrillator analyzes the rhythm, which may take up to 30 seconds. The machine then indicates if defibrillation is indicated. Rationale 2: Standard electrocardiographic monitoring leads are not used with an AED. Rationale 3: Defibrillator paddles are not used with an AED. Rationale 4: Telephone monitoring devices are not used with an AED. Global Rationale: The nurse applies adhesive patch electrodes to the patient's chest in the usual defibrillator positions, stops CPR, and orders everyone near the patient to move away and not touch the patient. The defibrillator analyzes the rhythm, which may take up to 30 seconds. The machine then indicates if defibrillation is indicated. Standard electrocardiographic monitoring leads, defibrillator paddles, and telephone monitoring devices are not used with an AED.

A patient is experiencing supraventricular tachycardia. Which medications should the nurse prepare to administer to this patient? Standard Text: Select all that apply. 1. verapamil (Calan) 2. diltiazem (Cardizem) 3. amlodipine (Norvasc) 4. propafenone (Rythmol) 5. adenosine (Adenocard)

Correct Answer: 1, 2, 3, 5 Rationale 1: Calcium channel blockers decrease automaticity and AV nodal conduction. They are used to manage supraventricular tachycardia. These medications include verapamil (Calan). Rationale 2: Calcium channel blockers decrease automaticity and AV nodal conduction. They are used to manage supraventricular tachycardia. These medications include diltiazem (Cardizem). Rationale 3: Calcium channel blockers decrease automaticity and AV nodal conduction. They are used to manage supraventricular tachycardia. These medications include amlodipine (Norvasc). Rationale 4: Propafenone (Rythmol) is used to reduce or eliminate tachydysthymias associated with reentry. Rationale 5: Adenosine (Adenocard) decreases conduction through the AV node and is used to treat supraventricular tachycardia. Global Rationale: Calcium channel blockers decrease automaticity and AV nodal conduction. They are used to manage supraventricular tachycardia. These medications include amlodipine (Norvasc), verapamil (Calan), and diltiazem (Cardizem). Adenosine (Adenocard) decreases conduction through the AV node and is used to treat supraventricular tachycardia. Propafenone (Rythmol) is used to reduce or eliminate tachydysthymias associated with reentry.

Sinus bradycardia (rate 56 beats per minute) is identified in a sleeping patient on telemetry. What is the priority nursing action? 1. Awaken the patient and see how the heart rate responds. 2. Call the physician and report this dysrhythmia. 3. Check the medication administration record and see if there is a PRN medication that will improve this rhythm. 4. Call for an immediate 12-lead electrocardiogram (ECG).

Correct Answer: 1 Rationale 1: The priority is to awaken the patient to determine how the heart rate is affected with activity as it normally should increase. The patient should be evaluated to determine how the dysrhythmia is affecting heart function. Many patients who are asymptomatic while in sinus bradycardia can be observed and require no further intervention. Common reasons for sinus bradycardia for the nurse to consider include athletic conditioning, sleep, or a conduction disorder. Rationale 2: Notifying the physician without first assessing the patient's response would not be appropriate. Rationale 3: Checking the medication administration is not the priority nursing action. Rationale 4: Ordering an ECG requires a physician's prescription. Global Rationale: The priority is to awaken the patient to determine how the heart rate is affected with activity as it normally should increase. The patient should be evaluated to determine how the dysrhythmia is affecting heart function. Many patients who are asymptomatic while in sinus bradycardia can be observed and require no further intervention. Common reasons for sinus bradycardia for the nurse to consider include athletic conditioning, sleep, or a conduction disorder. Notifying the physician without first assessing the patient's response would not be appropriate. Checking the medication administration is not the priority nursing action. Ordering an ECG requires a physician's prescription.

The nurse is caring for a patient with ventricular tachycardia. Which care should the nurse prepare to provide to this patient? Standard Text: Select all that apply. 1. immediate assessment and probable emergency intervention by the nurse 2. cardioversion, if sustained and symptomatic 3. administration of a potassium channel blocker 4. close observation for one hour prior to calling the physician

Correct Answer: 1, 2, 3 Rationale 1: Sustained ventricular tachycardia is a medical emergency that requires immediate intervention, particularly in patients with cardiac disease. Rationale 2: Treatment for ventricular tachycardia includes cardioversion. Rationale 3: Class III antidysrhythmic medications (potassium channel blockers) are typically administered. Rationale 4: Observation prior to calling a physician is not an appropriate action when a potentially life-threatening rhythm is identified. Rationale 5: Defibrillation is only conducted in ventricular tachycardia when the patient is pulseless; otherwise, time is taken to synchronize for cardioversion. Global Rationale: Sustained ventricular tachycardia is a medical emergency that requires immediate intervention, particularly in patients with cardiac disease. Treatment for ventricular tachycardia includes cardioversion. Class III antidysrhythmic medications (potassium channel blockers) are typically administered. Observation prior to calling a physician is not an appropriate action when a potentially life-threatening rhythm is identified. Defibrillation is only conducted in ventricular tachycardia when the patient is pulseless; otherwise, time is taken to synchronize for cardioversion.

A patient is in sinus tachycardia. Which nursing interventions are appropriate? Standard Text: Select all that apply. 1. Observe the patient for effects on cardiac function. 2. Administer two tablets of acetaminophen (Tylenol) per physician prescription if an elevated temperature is present. 3. Administer normal saline 0.9% IV at the prescribed rate of 200 mL per hour if hypovolemia is suspected as the cause. 4. Give pain medications as prescribed if pain is present. 5. Give atropine per physician prescription to slow the heart rate.

Correct Answer: 1, 2, 3, 4 Rationale 1: Appropriate nursing interventions for the patient in sinus tachycardia include observing the patient for effects on cardiac function. Rationale 2: Appropriate nursing interventions for the patient in sinus tachycardia include treating fever. Rationale 3: Appropriate nursing interventions for the patient in sinus tachycardia include treating hypovolemia. Rationale 4: Appropriate nursing interventions for the patient in sinus tachycardia include treating pain. Rationale 5: Atropine acts to increase heart rate and may be a cause of sinus tachycardia. Global Rationale: Appropriate nursing interventions for the patient in sinus tachycardia are to observe the patient for effects on cardiac function and to treat fever, hypovolemia, and pain if present. The focus is on determining the patient response to the elevated heart rate and treating the underlying causes, which are often fever, pain, and hypovolemia. Atropine acts to increase heart rate and may be a cause of sinus tachycardia.

The nurse is notified by the cardiac monitoring technician that a patient on continuous cardiac monitoring is having frequent alarms. When the nurse enters the patient's room, the patient is in no apparent distress, is sitting in the chair and eating. Which are appropriate nursing interventions? Standard Text: Select all that apply. 1. Confirm that lead wires are properly connected. 2. Assess placement of electrodes. 3. Remove and reapply new electrodes if nonadherent. 4. Assess skin sites and move an electrode if the skin appears irritated. 5. Call for assistance.

Correct Answer: 1, 2, 3, 4 Rationale 1: Nursing actions include assessing lead wire connections. Rationale 2: Nursing actions include assessing placement of electrodes. Rationale 3: Nursing actions include changing electrodes every 24 to 48 hours or removing and reapplying electrodes that are dislodged or nonadherent. Rationale 4: Nursing actions include assessing and documenting skin condition under the pads and moving pads to alternate sites to avoid skin irritation. Rationale 5: Since the patient is in no apparent distress, assistance is not required. Global Rationale: Alarms may be triggered by loose or disconnected lead wires, poor electrode contact, excessive movement, electrical interference, or equipment malfunction. Nursing actions include assessing lead wire connections; assessing placement of electrodes and changing electrodes every 24 to 48 hours or removing and reapplying electrodes that are dislodged or non-adherent; assessing and documenting skin condition under the pads and moving pads to alternate sites to avoid skin irritation; and documenting ECG strips according to unit policy. Since the patient is in no apparent distress, assistance is not required.

A client is receiving an intravenous lidocaine infusion after being converted from ventricular tachycardia. The client begins to display signs of confusion, anxiety, agitation, and restlessness. What should the nurse do first? 1. Increase the rate of lidocaine infusion. 2. Turn off the lidocaine infusion. 3. Administer oxygen at 4 L per nasal cannula. 4. Notify the client's health care provider.

Correct Answer: 2 Rationale 1: Increasing the rate of lidocaine would worsen symptoms and could lead to ventricular dysrhythmia and subsequent cardiac arrest. Rationale 2: The first signs of lidocaine toxicity usually involve the CNS and include confusion, anxiety, tremors, and other symptoms. The infusion should be discontinued immediately, and the health care provider notified. Rationale 3: Oxygen should be administered, but this is not the first action the nurse should take. Rationale 4: The health care provider should be notified, but this is not the first action the nurse should take. Global Rationale: The first signs of lidocaine toxicity usually involve the CNS and include confusion, anxiety, tremors, and other symptoms. The infusion should be discontinued immediately, and the health care provider notified. Increasing the rate of lidocaine would worsen symptoms and could lead to ventricular dysrhythmia and subsequent cardiac arrest. Oxygen should be administered, but this is not the first action the nurse should take. The health care provider should be notified, but this is not the first action the nurse should take.

A client with a history of congestive heart failure is prescribed propranolol (Inderal) for control of ventricular tachycardia. Which instruction is most important for the nurse to provide to this client? 1. "Report nausea to your health care provider." 2. "Immediately report an increase of shortness of breath or weight gain of 2 pounds over 1 day." 3. "Weigh yourself each day at approximately the same time, with the same amount of clothing." 4. "Exercise at least 30 minutes daily."

Correct Answer: 2 Rationale 1: Symptoms of nausea should be reported, but this is not the most important issue. Rationale 2: Propranolol (Inderal) reduces myocardial automaticity, thereby potentially reducing cardiac output and exasperating symptoms of CHF. Symptoms of CHF should be reported immediately when taking a beta blocker. Rationale 3: Weighing should occur daily at the same time, but this is not the most important instruction. Rationale 4: Clients should exercise 30 minutes daily, but this is not the most important instruction. Global Rationale: Propranolol (Inderal) reduces myocardial automaticity, thereby potentially reducing cardiac output and exasperating symptoms of CHF. Symptoms of CHF should be reported immediately when taking a beta blocker. Symptoms of nausea should be reported, but this is not the most important issue. Weighing should occur daily at the same time, but this is not the most important instruction. Clients should exercise 30 minutes daily, but this is not the most important instruction.

A client scheduled for a catheter ablation to treat atrial fibrillation says, "I am not sure about this procedure. Can they just treat me with medicine?" Which response by the nurse is the most appropriate? 1. "Many people do take drugs for atrial fibrillation. Your case must be different." 2. "Catheter ablation is more successful and has fewer long-term adverse effects than drug therapy." 3. "Most of the medications used for atrial fibrillation have been taken off the market." 4. "Atrial fibrillation is too dangerous to be treated with medications alone."

Correct Answer: 2 Rationale 1: The nurse has not answered the client's question and may have increased the client's confusion. Rationale 2: Catheter ablation has been shown to be more successful in treating many dysrhythmias than is the prophylactic use of medications. The treatment is generally definitive and results in fewer adverse effects. Rationale 3: Medications for the control of atrial fibrillation are still on the market. Rationale 4: Atrial fibrillation does have serious consequences in some cases, but many clients are managed with medication therapy alone. Global Rationale: Catheter ablation has been shown to be more successful in treating many dysrhythmias than is the prophylactic use of medications. The treatment is generally definitive and results in fewer adverse effects. The nurse has not answered the client's question and may have increased the client's confusion. Medications for the control of atrial fibrillation are still on the market. Atrial fibrillation does have serious consequences in some cases, but many clients are managed with medication therapy alone.

A client is prescribed oral verapamil (Calan) for the treatment of atrial fibrillation. Which statement indicates that the client understands the medication teaching provided by the nurse? 1. "I should not take the medication with grapefruit." 2. "This medication will slow my heart rate so I will not get so fatigued." 3. "This medication will allow my heart to go back into normal, regular rhythm." 4. "Taking this medication might cause me to need a pacemaker."

Correct Answer: 2 Rationale 1: There is no drug-food interaction between verapamil and grapefruit. Rationale 2: Calcium channel blockers like verapamil prolong the PR interval, thereby controlling ventricular rate in cases of atrial fibrillation. Rationale 3: Verapamil (Calan) slows ventricular rate but is unlikely to cause conversion to normal sinus rhythm. Rationale 4: If the heart rate became too slow due to the effects of the calcium channel blocker, then the medication would be discontinued. It would be a rare emergency for the heart rate to get so low that a pacemaker would be necessary. Global Rationale: Calcium channel blockers like verapamil prolong the PR interval, thereby controlling ventricular rate in cases of atrial fibrillation. There is no drug-food interaction between verapamil and grapefruit. Verapamil (Calan) slows ventricular rate but is unlikely to cause conversion to normal sinus rhythm. If the heart rate became too slow due to the effects of the calcium channel blocker, then the medication would be discontinued. It would be a rare emergency for the heart rate to get so low that a pacemaker would be necessary.

The nurse notes a widely bizarre pattern on the client's cardiac monitor. What is the nurse's priority action? 1. Call a code blue. 2. Check the client's pulse. 3. Immediately defibrillate the client. 4. Check the rhythm in a different lead.

Correct Answer: 2 Rationale 1: This is not the first thing that the nurse should do. Rationale 2: The nurse should always remember to verify any changes on the cardiac monitor by assessing the client (in this case, checking the pulse). The cardiac monitor reports electrical activity that may not directly reflect the mechanical activity occurring in the heart. Rationale 3: The nurse should not immediately defibrillate the client. Rationale 4: The nurse should not check the rhythm in a different lead first.

A client who underwent cardioversion for atrial fibrillation is prescribed amiodarone (Cordarone). Which testing should the nurse ensure has been completed before the client starts this medication? 1. A hearing test 2. A fasting blood sugar 3. A pulmonary lung function test 4. A 24-hour urine test for creatinine

Correct Answer: 3 Rationale 1: Amiodarone does not affect hearing. Rationale 2: Amiodarone does not have a direct effect on blood sugar levels. Rationale 3: The most serious side effect of amiodarone can occur in the lungs. Because pulmonary toxicity can be fatal, baseline and periodic assessment of lung function is essential. Rationale 4: Amiodarone is excreted primarily through the liver. There is no reason to obtain a 24-hour urine test for creatinine. Global Rationale: The most serious side effect of amiodarone can occur in the lungs. Because pulmonary toxicity can be fatal, baseline and periodic assessment of lung function is essential. Amiodarone does not affect hearing or have a direct effect on blood sugar levels. Amiodarone is excreted primarily through the liver. There is no reason to obtain a 24-hour urine test for creatinine.

Which client in a cardiac step-down unit would the nurse monitor most closely for the development of cerebral vascular accident (CVA) or stroke? 1. An 80-year-old client whose cardiac monitor reveals bradycardia with a rate of 58 2. A 56-year-old client with a PR interval of 0.22 seconds 3. A 37-year-old client with recent-onset atrial fibrillation 4. A 63-year-old client with occasional premature ventricular contractions (PVCs)

Correct Answer: 3 Rationale 1: Bradyarrhythmias are common in older adults, and a heart rate of 58 is not the most significant indicator of risk of stroke. Rationale 2: Prolongation of the PR interval is not normal but is not a precursor of stroke. Rationale 3: Atrial fibrillation slows the movement of blood through the chambers of the heart and may result in clot formation. If a clot is ejected from the heart into the systemic circulation, a stroke may occur. Rationale 4: Occasional PVCs are common and are not a precursor of stroke. Global Rationale: Atrial fibrillation slows the movement of blood through the chambers of the heart and may result in clot formation. If a clot is ejected from the heart into the systemic circulation, a stroke may occur. Bradyarrhythmias are common in older adults, and a heart rate of 58 is not the most significant indicator of risk of stroke. Prolongation of the PR interval is not normal but is not a precursor of stroke. Occasional PVCs are common and are not a precursor of stroke.

The nurse is preparing to administer procainamide (Pronestyl) intravenously for conversion of atrial flutter. How should the nurse position the client? 1. In Trendelenburg position 2. Prone 3. Supine 4. With the head of the bed elevated

Correct Answer: 3 Rationale 1: The Trendelenburg position would be used in the event of a hypotensive episode. Rationale 2: The prone position is not used because it inhibits access to the airway. Rationale 3: The supine position should be maintained with IV infusion of Pronestyl due to the increased risk of hypotension. Rationale 4: The head of the bed should not be elevated due to risk of hypotension with IV infusion of Pronestyl. Global Rationale: The supine position should be maintained with IV infusion of Pronestyl due to the increased risk of hypotension. The Trendelenburg position would be used in the event of a hypotensive episode. The prone position is not used because it inhibits access to the airway. The head of the bed should not be elevated due to risk of hypotension with IV infusion of Pronestyl.

The nurse admits a client to the emergency department with new-onset atrial fibrillation and a heart rate of 168 beats per minute. The client is complaining of dizziness and shortness of breath. The nurse starts an intravenous line in anticipation of administering which drug? 1. Digoxin (Lanoxin) 2. Disopyramide (Norpace) 3. Ibutilide (Corvert) 4. Lidocaine (Xylocaine)

Correct Answer: 3 Rationale 1: While digoxin (Lanoxin) may be prescribed to help control the ventricular rate associated with atrial fibrillation, it would not be the drug of choice for a new-onset atrial fibrillation that could be converted to normal sinus rhythm. Rationale 2: Disopyramide (Norpace) is usually only given to clients with life-threatening ventricular tachycardia. Rationale 3: Ibutilide (Corvert) is a drug of choice for rapidly converting atrial fibrillation to normal sinus rhythm. Rationale 4: Lidocaine (Xylocaine) is not effective in treating atrial dysrhythmias. Global Rationale: Ibutilide (Corvert) is a drug of choice for rapidly converting atrial fibrillation to normal sinus rhythm. While digoxin (Lanoxin) may be prescribed to help control the ventricular rate associated with atrial fibrillation, it would not be the drug of choice for a new-onset atrial fibrillation that could be converted to normal sinus rhythm. Disopyramide (Norpace) is usually only given to clients with life-threatening ventricular tachycardia. Lidocaine (Xylocaine) is not effective in treating atrial dysrhythmias.

The client has experienced a myocardial infarction with damage to the inferior portion of the heart. Due to this history, the nurse monitors the client for the development of rhythm disturbances that are most directly based upon which factor?

Correct Answer: 3 Rationale: Each cardiac cell can generate its own electrical impulse. Myocardial infarction interferes with the flow of blood to these cells, and the resultant ischemia makes the cells more irritable and more likely to generate an impulse. These uncontrolled impulses result in rhythm disturbances. Although extreme changes in blood sugar can result in cardiac disturbances, the most likely cause of rhythm disturbance following myocardial infarction is insult to the cells causing them to be irritable.

A client diagnosed with atrial fibrillation is prescribed a calcium channel blocker to help control the ventricular rate. The nurse plans to monitor the client's cardiac rhythm strip for which change? 1. Widening of the QRS complex 2. Widening of the QT interval 3. Inverted T waves 4. Prolongation of the PR interval

Correct Answer: 4 Rationale 1: Calcium channel blockers do not widen the QRS. Rationale 2: Calcium channel blockers do not widen the QT. Rationale 3: Calcium channel blockers do not cause T wave changes. Rationale 4: Prolonging the refractory period by calcium channel blockade causes prolongation of the PR interval. Global Rationale: Prolonging the refractory period by calcium channel blockade causes prolongation of the PR interval. Calcium channel blockers do not widen the QRS or the QT and they don't cause T wave changes.

A client is admitted to the emergency department (ED) with new-onset atrial fibrillation. Which cardiac rhythm history would be a contraindication for the use of a sodium channel blocker antidysrhythmic medication? 1. Occasional premature ventricular contractions (PVCs) 2. Multiple premature atrial contractions (PACs) 3. Elevated blood sugar 4. Second-degree AV block

Correct Answer: 4 Rationale 1: Sodium channel blockers may be used to control PVCs. Rationale 2: Sodium channel blockers may be used to control PACs. Rationale 3: Sodium channel blockers do not have a direct correlation with blood sugar levels. Rationale 4: Sodium channel blockers slow the action potential and delay conduction, therefore risking complete heart block and cardiac arrest if used on a client with a history of existing second- or third-degree block. Global Rationale: Sodium channel blockers slow the action potential and delay conduction, therefore risking complete heart block and cardiac arrest if used on a client with a history of existing second- or third-degree block. Sodium channel blockers may be used to control PVCs, PACs, and do not have a direct correlation with blood sugar levels.

ANS: B Also called a Mobitz I or Wenckebach phenomenon, second-degree AV block type I is represented on the ECG as a progressive lengthening of the PR interval until there is a P wave without a QRS complex. In first-degree AV block, a P wave precedes every QRS complex, and every P wave is followed by a QRS; however, the PR interval is >0.20 seconds. Second-degree AV block type II (Mobitz II) is a more critical type of heart block that requires early recognition and intervention. There is no progressive lengthening of the PR interval, which remains the same throughout with the exception of the dropped beat(s). Third-degree block is often called complete heart block because no atrial impulses are conducted through the AV node to the ventricles. In complete heart block, the atria and ventricles beat independently of each other because the AV node is completely blocked to the sinus impulse and it is not conducted to the ventricles. One hallmark of third-degree heart block is that the P waves have no association with the QRS complexes and appear throughout the QRS waveform.

Interpret the following rhythm: a. First-degree AV block b. Second-degree AV block Mobitz I (Wenckebach phenomenon) c. Second-degree AV block Mobitz II d. Third-degree AV block (complete heart block)

ANS: C Second-degree AV block type II (Mobitz II) is a more critical type of heart block that requires early recognition and intervention. There is no progressive lengthening of the PR interval, which remains the same throughout with the exception of the dropped beat(s). Also called a Mobitz I or Wenckebach phenomenon, second-degree AV block type I is represented on the ECG as a progressive lengthening of the PR interval until there is a P wave without a QRS complex. In first-degree AV block, a P wave precedes every QRS complex, and every P wave is followed by a QRS. Third-degree block is often called complete heart block because no atrial impulses are conducted through the AV node to the ventricles. In complete heart block, the atria and ventricles beat independently of each other because the AV node is completely blocked to the sinus impulse and it is not conducted to the ventricles. One hallmark of third-degree heart block is that the P waves have no association with the QRS complexes and appear throughout the QRS waveform.

Interpret the following rhythm: a. First-degree AV block b. Second-degree AV block Mobitz I (Wenckebach phenomenon) c. Second-degree AV block Mobitz II d. Third-degree AV block (complete heart block)

ANS: B Pacemakers may be used to stimulate the atrium, ventricle, or both chambers (dual-chamber pacemakers). Atrial pacing is used to mimic normal conduction and to produce atrial contraction, thus providing atrial kick. Ventricular pacing stimulates ventricular depolarization and is commonly used in emergency situations or when pacing is required infrequently. This patient's pacemaker is stimulating the ventricles. Dual-chamber pacing allows for stimulation of both atria and ventricles as needed to synchronize the chambers and mimic the normal cardiac cycle. There is no evidence of a dual pacemaker since the atrial spike is not seen on the ECG strip. Transcutaneous pacing is accomplished via skin electrodes.

Interpret the following rhythm: a. Atrial pacing b. Ventricular pacing c. Dual-chamber pacing d. Transcutaneous pacing

ANS: C Pacemakers may be used to stimulate the atrium, ventricle, or both chambers (dual-chamber pacemakers). Atrial pacing is used to mimic normal conduction and to produce atrial contraction, thus providing atrial kick. Ventricular pacing stimulates ventricular depolarization and is commonly used in emergency situations or when pacing is required infrequently. Dual-chamber pacing allows for stimulation of both atria and ventricles as needed to synchronize the chambers and mimic the normal cardiac cycle. This is the case in the scenario provided as seen by pacemaker spikes in both the atrial and ventricular position.

Interpret the following rhythm: a. Atrial pacing b. Ventricular pacing c. Dual-chamber pacing d. Transcutaneous pacing

ANS: D Third-degree block is often called complete heart block because no atrial impulses are conducted through the AV node to the ventricles. In complete heart block, the atria and ventricles beat independently of each other because the AV node is completely blocked to the sinus impulse and it is not conducted to the ventricles. One hallmark of third-degree heart block is that the P waves have no association with the QRS complexes and appear throughout the QRS waveform. Second-degree AV block type II (Mobitz II) is a more critical type of heart block that requires early recognition and intervention. There is no progressive lengthening of the PR interval, which remains the same throughout with the exception of the dropped beat(s). Also called a Mobitz I or Wenckebach phenomenon, second-degree AV block type I is represented on the ECG as a progressive lengthening of the PR interval until there is a P wave without a QRS complex. In first-degree AV block, a P wave precedes every QRS complex, and every P wave is followed by a QRS.

Interpret the following rhythm: a. First-degree AV block b. Second-degree AV block Mobitz I (Wenckebach phenomenon) c. Second-degree AV block Mobitz II d. Third-degree AV block (complete heart block)

ANS: A Idioventricular rhythm is an escape rhythm that is generated by the Purkinje fibers. This rhythm emerges only when the SA and AV nodes fail to initiate an impulse. The Purkinje fibers are capable of an intrinsic rate of 20 to 40 beats per minute. Because this last pacemaker is located in the ventricles, the QRS complex appears wide and bizarre with a slow rate. No P waves are present. If the rate is between 40 and 100 beats per minute, this rhythm is called accelerated idioventricular rhythm (AIVR). Ventricular tachycardia (VT) is a rapid, life-threatening dysrhythmia originating from a single ectopic focus in the ventricles. It is characterized by at least three PVCs in a row. VT occurs at a rate greater than 100 beats per minute, but the rate is usually around 150 beats per minute and may be up to 250 beats per minute. VF produces a wavy baseline without a PQRST complex. Because a loose lead or electrical interference can produce a waveform similar to VF, it is always important to immediately assess the patient for pulse and consciousness.

Interpret the following rhythm: a. Idioventricular rhythm b. Accelerated idioventricular rhythm c. Ventricular tachycardia d. Ventricular fibrillation

ANS: A The normal intrinsic rate for the AV node and junctional tissue is 40 to 60 beats per minute, but rates can accelerate. An accelerated junctional rhythm has a rate between 60 and 100 beats per minute, and the rate for junctional tachycardia is greater than 100 beats per minute. If a P wave precedes QRS, it is inverted or upside down; the P wave may not be visible, or it may follow the QRS. If a P wave is present before the QRS, the PR interval is shortened to less than 0.12 milliseconds. Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. The AV node is bombarded with hundreds of atrial impulses and conducts these impulses in an unpredictable manner to the ventricles.

Interpret the following rhythm: a. Junctional rhythm b. An accelerated junctional rhythm c. A junctional tachycardia d. Atrial fibrillation

ANS: C Failure to pace or fire occurs when the pacemaker fails to initiate an electrical stimulus when it should fire. The problem is noted by absence of pacer spikes on the rhythm strip. Note that after the 3-second mark, the pacemaker failed to fire. When the pacemaker generates an electrical impulse (pacer spike) and no depolarization is noted, it is described as a failure to capture. On the ECG, a pacer spike is noted, but it is not followed by a P wave (atrial pacemaker) or a QRS complex (ventricular pacemaker) within the appropriate time frame. When the pacemaker does not sense the patient's own cardiac rhythm and initiates an electrical impulse, it is called failure to sense. Failure to sense manifests as pacer spikes that fall too closely to the patient's own rhythm, earlier than the programmed rate. This is not normal pacemaker function.

Interpret the following rhythm: a. Normal pacemaker function b. Failure to capture c. Failure to pace d. Failure to sense

ANS: A Normal sinus rhythm (NSR) reflects normal conduction of the sinus impulse through the atria and ventricles. Atrial and ventricular rates are the same and range from 60 to 100 beats per minute. Rhythm is regular or essentially regular. PR interval is 0.12 to 0.20 seconds. QRS interval is 0.06 to 0.10 seconds. P and QRS waves are consistent in shape. Sinus tachycardia results when the SA node fires faster than 100 beats per minute. Bradycardia is defined as a heart rate less than 60 beats per minute. Sinus arrhythmia is a cyclical change in heart rate that is associated with respiration. The heart rate slightly increases during inspiration and slightly slows during exhalation because of changes in vagal tone.

Interpret the following rhythm: a. Normal sinus rhythm b. Sinus bradycardia c. Sinus tachycardia d. Sinus arrhythmia

ANS: D In first-degree block, P and QRS waves are consistent in shape. P waves are small and rounded. A P wave precedes every QRS complex, which is followed by a T wave. PR interval is prolonged and is greater than 0.20 seconds. QRS complex and QT/QTc measurements are normal. Normal sinus rhythm (NSR) reflects normal conduction of the sinus impulse through the atria and ventricles. Atrial and ventricular rates are the same and range from 60 to 100 beats per minute. Rhythm is regular or essentially regular. PR interval is 0.12 to 0.20 seconds. In a complete heart block, the atria and ventricles beat independently of each other. A first-degree AV block means the PR interval is greater than 0.20 seconds.

Interpret the following rhythm: a. Normal sinus rhythm b. Sinus rhythm with second-degree AV block c. Complete heart block d. Sinus rhythm with first-degree AV block

ANS: A The peak of the T wave through the downslope of the T wave is considered the vulnerable period, which coincides with partial repolarization of the ventricles. If a PVC occurs during the T wave, ventricular tachycardia may occur. When the R wave of a PVC falls on the T wave of a normal beat, it is referred to as the R-on-T phenomenon. This strip does not show sinus rhythm, multi-focal PVCs (PVCs that are from different places in the heart and therefore look different), non-sustained ventricular tachycardia, or bigeminal premature ventricular contractions (where every other beat is a PVC).

Interpret the following rhythm: a. R-on-T phenomenon leading to ventricular fibrillation b. Sinus rhythm with multifocal premature ventricular contractions c. Nonsustained ventricular tachycardia d. Sinus rhythm with bigeminal premature ventricular contractions

ANS: A The underlying rhythm is identified first. Following this step, the dysrhythmia that is occurring to disrupt the underlying rhythm is then determined. A premature atrial contraction (PAC) is a single ectopic beat arising from atrial tissue, not the sinus node. The PAC occurs earlier than the next normal beat and interrupts the regularity of the underlying rhythm. The P wave of the PAC has a different shape than the sinus P wave because it arises from a different area in the atria; it may follow or be in the T wave of the preceding normal beat. If the early P wave is in the T wave, this T wave will look different from the T wave of a normal beat. Normal sinus rhythm (NSR) reflects normal conduction of the sinus impulse through the atria and ventricles. Atrial and ventricular rates are the same and range from 60 to 100 beats per minute. Rhythm is regular or essentially regular. PR interval is 0.12 to 0.20 seconds. QRS interval is 0.06 to 0.10 seconds. P and QRS waves are consistent in shape. Sinus tachycardia results when the SA node fires faster than 100 beats per minute. Bradycardia is defined as a heart rate less than 60 beats per minute.

Interpret the following rhythm: a. Sinus rhythm with PACs b. Normal sinus rhythm c. Sinus tachycardia d. Sinus bradycardia

ANS: A A single ectopic focus produces PVC waveforms that look alike, called unifocal PVCs. Waveforms of PVCs arising from multiple foci are not identical and are called multifocal PVCs. PVCs may occur in a predictable pattern, such as every other beat (bigeminal), every third beat (trigeminal), or every fourth beat (quadrigeminal). PVCs can also occur sequentially. Two PVCs in a row are called a pair (or couplets), and three or more in a row are called nonsustained ventricular tachycardia.

Interpret the following rhythm: a. Sinus rhythm with multifocal premature ventricular contractions b. Sinus rhythm with unifocal premature ventricular contractions c. Sinus rhythm with bigeminal premature ventricular contractions d. Sinus rhythm with paired premature ventricular contractions (couplets)

ANS: C A single ectopic focus produces PVC waveforms that look alike, called unifocal PVCs. Waveforms of PVCs arising from multiple foci are not identical and are called multifocal PVCs. PVCs may occur in a predictable pattern, such as every other beat (bigeminal), every third beat (trigeminal), or every fourth beat (quadrigeminal). PVCs can also occur sequentially. Two PVCs in a row are called a pair (couplet), and three or more in a row are called nonsustained ventricular tachycardia.

Interpret the following rhythm: a. Sinus rhythm with multifocal premature ventricular contractions b. Sinus rhythm with unifocal premature ventricular contractions c. Sinus rhythm with bigeminal premature ventricular contractions d. Sinus rhythm with paired premature ventricular contractions (couplets)

ANS: D A single ectopic focus produces PVC waveforms that look alike, called unifocal PVCs. Waveforms of PVCs arising from multiple foci are not identical and are called multifocal PVCs. PVCs may occur in a predictable pattern, such as every other beat (bigeminal), every third beat (trigeminal), or every fourth beat (quadrigeminal). PVCs can also occur sequentially. Two PVCs in a row are called a pair (couplet), and three or more in a row are called nonsustained ventricular tachycardia.

Interpret the following rhythm: a. Sinus rhythm with multifocal premature ventricular contractions b. Sinus rhythm with unifocal premature ventricular contractions c. Sinus rhythm with bigeminal premature ventricular contractions d. Sinus rhythm with paired premature ventricular contractions (couplets)

ANS: B A single ectopic focus produces PVC waveforms that look alike, called unifocal PVCs. Waveforms of PVCs arising from multiple foci are not identical and are called multifocal PVCs. PVCs may occur in a predictable pattern, such as every other beat (bigeminal), every third beat (trigeminal), or every fourth beat (quadrigeminal). PVCs also can occur sequentially. Two PVCs in a row are called a pair, and three or more in a row are called nonsustained ventricular tachycardia.

Interpret the following rhythm: a. Sinus rhythm with multifocal premature ventricular contractions b. Sinus rhythm with unifocal premature ventricular contractions c. Sinus rhythm with trigeminal premature ventricular contractions d. Sinus rhythm with paired premature ventricular contractions (couplets)