Ch. 26 Management of Pts w Dysrhythmias & Conduction Problems

A home care nurse is visiting a left-handed client who has an implantable cardioverter-defibrillator (ICD) implanted in the left chest. The client is planning to go rifle hunting. How should the nurse respond?

"You can't shoot a rifle left-handed because the rifle's recoil will traumatize the ICD site."- The recoil from the rifle can damage the ICD, so the client should be warned against shooting a rifle with the left hand. Close proximity to a rifle won't cause the ICD to fire inadvertently. The client shouldn't take an extra dose of an antiarrhythmic.

A client's electrocardiogram (ECG) tracing reveals a atrial rate between 250 and 400, with saw-toothed P waves. The nurse correctly identifies this dysrhythmia as

Atrial flutter- The nurse correctly identifies the electrocardiogram (ECG) tracing as atrial flutter. Atrial flutter occurs in the atrium and creates impulses at a regular atrial rate between 250 and 400 times per minute. The P waves are saw-toothed in appearance. Atrial fibrillation causes a rapid, disorganized, and uncoordinated twitching of atrial musculature. The atrial rate is 300 to 600, and the ventricular rate is usually 120 to 200 in untreated atrial fibrillation. There are no discernible P waves. Ventricular fibrillation is a rapid, disorganized ventricular rhythm that causes ineffective quivering of the ventricles. The ventricular rate is greater than 300 per minute and extremely irregular, without a specific pattern. The QRS shape and duration is irregular, undulating waves without recognizable QRS complexes. Ventricular tachycardia is defined as three or more PVCs in a row, occurring at a rate exceeding 100 beats per minute.

The nurse documents that a client is having a normal sinus rhythm. What characteristics of this rhythm has the nurse assessed?

The sinoatrial (SA) node initiates the impulse.- The characteristics of normal sinus rhythm are heart rate between 60 and 100 beats per minute; the SA node initiates the impulse; the impulse travels to the AV node in 0.12 to 0.2 seconds; the ventricles depolarize in 0.12 seconds or less; and each impulse occurs regularly.

A client experiences a faster-than-normal heart rate when drinking more than two cups of coffee in the morning. What does the nurse identify on the electrocardiogram as an indicator of sinus tachycardia?

heart rate of 118 bpm- The sinus node creates an impulse at a faster-than-normal rate. The PR interval of 0.1 seconds, QRS duration of 0.16 seconds and Q wave of 0.04 seconds are consistent with a normal sinus rhythm. Sinus tachycardia occurs when the heart rate is over 100 bpm.

The nurse assesses a client with a heart rate of 120 beats per minute. What are the known causes of sinus tachycardia?

hypovolemia- The causes of sinus tachycardia include physiologic or psychological stress (acute blood loss, anemia, shock, hypovolemia, fever, and exercise). Vagal stimulation, hypothyroidism, and digoxin will cause a sinus bradycardia.

A client asks the nurse what causes the heart to be an effective pump. The nurse informs the client that this is due to the:

inherent rhythmicity of cardiac muscle tissue.- Cardiac rhythm refers to the pattern (or pace) of the heartbeat. The conduction system of the heart and the inherent rhythmicity of cardiac muscle produce a rhythm pattern, which greatly influences the heart's ability to pump blood effectively.

The nurse is monitoring a patient in the postanesthesia care unit (PACU) following a coronary artery bypass graft, observing a regular ventricular rate of 82 beats/min and "sawtooth" P waves with an atrial rate of approximately 300 beat/min. How does the nurse interpret this rhythm?

Atrial flutter- Atrial flutter occurs because of a conduction defect in the atrium and causes a rapid, regular atrial rate, usually between 250 and 400 bpm and results in P waves that are saw-toothed. Because the atrial rate is faster than the AV node can conduct, not all atrial impulses are conducted into the ventricle, causing a therapeutic block at the AV node. This is an important feature of this dysrhythmia. If all atrial impulses were conducted to the ventricle, the ventricular rate would also be 250 to 400 bpm, which would result in ventricular fibrillation, a life-threatening dysrhythmia. Atrial flutter often occurs in patients with chronic obstructive pulmonary disease, pulmonary hypertension, valvular disease, and thyrotoxicosis, as well as following open heart surgery and repair of congenital cardiac defects (Fuster, Walsh et al., 2011).

The nurse knows that electrocardiogram (ECG) characteristics of atrial fibrillation include what?

Atrial rate of 300 to 400- ECG characteristics of atrial fibrillation include an atrial rate of 300 to 400, a nonmeasurable PR interval, irregular rhythm, and no discernible P waves.

A nurse completes a shift assessment on a client admitted to the telemetry unit with a diagnosis of syncope. The client's heart rate is 55 bpm with a blood pressure of 90/66 mm Hg. The client is also experiencing dizziness and shortness of breath. Which medication will the nurse anticipate administering to the client based on these clinical findings?

Atropine- The client is demonstrating signs and symptoms of symptomatic sinus bradycardia. Atropine is the medication of choice in treating symptomatic sinus bradycardia. Lidocaine treats ventricular dysrhythmias. Pronestyl treats and prevents atrial and ventricular dysrhythmias. Cardizem is a calcium channel blocker and treats atrial dysrhythmias.

A patient is 2 days postoperative after having a permanent pacemaker inserted. The nurse observes that the patient is having continuous hiccups as the patient states, "I thought this was normal." What does the nurse understand is occurring with this patient?

Lead wire dislodgement-Phrenic nerve, diaphragmatic (hiccupping may be a sign), or skeletal muscle stimulation may occur if the lead is dislocated or if the delivered energy (mA) is set high. The occurrence of this complication is avoided by testing during device implantation.

A client admitted to the telemetry unit has a serum potassium level of 6.6 mEq/L. Which electrocardiographic (ECG) characteristic is commonly associated with this laboratory finding?

Peaked T waves- The client's serum potassium level is high. The T wave is an ECG characteristic reflecting repolarization of the ventricles. It may become tall or "peaked" if a client's serum potassium level is high. The U wave is an ECG waveform characteristic that may reflect Purkinje fiber repolarization. It is usually seen when a client's serum potassium level is low. The P wave is an ECG characteristic reflecting conduction of an electrical impulse through the atria and is not affected by a client's serum potassium level. The QT interval is an ECG characteristic reflecting the time from ventricular depolarization to repolarization, and is not affected by a client's serum potassium level.

A 28-year-old client presents to the emergency department, stating severe restlessness and anxiety. Upon assessment, the client's heart rate is 118 bpm and regular, the client's pupils are dilated, and the client appears excitable. Which action should the nurse take next?

Question the client about alcohol and illicit drug use.- The client is experiencing sinus tachycardia. Since the client's findings of tachycardia, dilated pupils, restlessness, anxiety, and excitability can indicate illicit drug use (cocaine), the nurse should question the client about alcohol and illicit drug use. This information will direct the client's plan of care. Causes of tachycardia include medications that stimulate the sympathetic response, stimulants, and illicit drugs. The treatment goals for sinus tachycardia is usually determined by the severity of symptoms and directed at identifying and abolishing its cause. The other interventions may be implemented, but determining the cause of the tachycardia is essential.

The nurse is teaching a beginning EKG class to staff nurses. As the nurse begins to discuss the parts of the EKG complex, one of the students asks what the normal order of conduction through the heart is. What order does the nurse describe?

Sinoatrial (SA) node, atrioventricular (AV) node, bundle of His, right and left bundle branches, and the Purkinje fibers- The correct sequence of conduction through the normal heart is the SA node, AV node, bundle of His, right and left bundle branches, and Purkinje fibers.

A patient comes to the emergency department with reports of chest pain after using cocaine. The nurse assesses the patient and obtains vital signs with results as follows: blood pressure 140/92, heart rate 128, respiratory rate 26, and an oxygen saturation of 98%. What rhythm on the monitor does the nurse anticipate viewing?

Sinus tachycardia- Sinus tachycardia occurs when the sinus node creates an impulse at a faster-than-normal rate. Causes include medications that stimulate the sympathetic response (e.g., catecholamines, aminophylline, atropine), stimulants (e.g., caffeine, nicotine), and illicit drugs (e.g., amphetamines, cocaine, Ecstasy).

The client has just been diagnosed with a dysrhythmia. The client asks the nurse to explain normal sinus rhythm. What would the nurse explain is the characteristic of normal sinus rhythm?

The sinoatrial (SA) node initiates the impulse.- The characteristics of normal sinus rhythm are heart rate between 60 and 100 beats/minute, the SA node initiates the impulse, the impulse travels to the AV node in 0.12 to 0.2 second, the ventricles depolarize in 0.12 seconds or less, and each impulse occurs regularly.

A client's Holter monitor strip reveals a heart rate with normal conduction but with a rate consistently above 105 beats/minute. What other conditions can cause this response in a healthy heart?

There are a variety of causes that can create an elevated heart rate in an otherwise healthy heart, including fever, shock, and strenuous exercise.

When no atrial impulse is conducted through the AV node into the ventricles, the client is said to be experiencing which type of AV block?

Third degree- In third degree heart block, two impulses stimulate the heart, one impulse stimulates the ventricles and other stimulates the atria. In first degree heart block, all the atrial impulses are conducted through the AV node into the ventricles at a rate slower than normal. In second degree AV block, type I, all but one of the atrial impulses are conducted through the AV node into the ventricles. In second degree AV block, type II, only some of the atrial impulses are conducted through the AV node into the ventricles.

Which nursing intervention must a nurse perform when administering prescribed vasopressors to a client with a cardiac dysrhythmia?

Which nursing intervention must a nurse perform when administering prescribed vasopressors to a client with a cardiac dysrhythmia? - The nurse should monitor the client's vital signs and cardiac rhythm for effectiveness of the medication and for side effects and should always have emergency life support equipment available when caring for an acutely ill client. The side effects of vasopressor drugs are hypertension, dysrhythmias, pallor, and oliguria. It is not necessary to place a client flat during or after vasopressor administration. When administering cholinergic antagonists, documentation of the heart rate is necessary.

The nurse is proving discharge instructions for a client with a new arrhythmia. Which statement should the nurse include?

Your family and friends may want to take a CPR class.- Having friends and family learn to perform CPR will help the client manage the arrhythmia. Monitoring pulse rate at home also helps the client manage the condition. Antiarrhythmic medication should be taken on time. Lightheadedness and dizziness should be reported to the provider.

A client tells the nurse "my heart is skipping beats again; I'm having palpitations." After completing a physical assessment, the nurse concludes the client is experiencing occasional premature atrial complexes (PACs). The nurse should instruct the client to

avoid caffeinated beverages.- If premature atrial complexes (PACs) are infrequent, no medical interventions are necessary. Causes of PACs include caffeine, alcohol, nicotine, stretched atrial myocardium (e.g., as in hypervolemia), anxiety, hypokalemia (low potassium level), hypermetabolic states (e.g., with pregnancy), or atrial ischemia, injury, or infarction. The nurse should instruct the client to avoid caffeinated beverages.

The nurse knows that what PR interval presents a first-degree heart block?

0.24 seconds- In adults, the normal range for the PR is 0.12 to 0.20 seconds. A PR internal of 0.24 seconds would indicate a first-degree heart block.

A nurse is teaching the client about the causes of fast heart rates. What client statement indicates the client requires more teaching?

"I will drink coffee with only two of my meals."-Stimulation of the sympathetic nervous system with caffeinated beverages, smoking, and drinking alcohol increases heart rate. The client is still drinking caffeine with two meals, increasing the risk for a fast heart rate. Taking medications such as metoprolol and levothyroxine will help the client maintain a normal heart rate by decreasing stimulation of the sympathetic nervous system.

Two nursing students are reading EKG strips. One of the students asks the instructor what the P-R interval represents. The correct response should be which of the following?

"It shows the time needed for the SA node impulse to depolarize the atria and travel through the AV node."- The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex and represents the time needed for sinus node stimulation, atrial depolarization, and conduction through the AV node before ventricular depolarization. In a normal heart the impulses do not travel backward. The PR interval does not include the time it take to travel through the Purkinje fibers.

A client is unconscious on arrival to the emergency department. The nurse in the emergency department identifies that the client has a permanent pacemaker due to which characteristic?

"Spike" on the rhythm strip- Confirmation that the client has a permanent pacemaker is the characteristic "spike" identified by a thin, straight stroke on the rhythm strip. The scar on the chest is suggestive of pacer implantation but not definitive. There should be no change in pulse quality, and no vibration under the skin.

The nursing student asks the nurse to describe the difference between sinus rhythm and sinus bradycardia on the electrocardiogram strip. What is the nurse's best reply?

"The only difference is the heart rate."-All characteristics of sinus bradycardia are the same as those of normal sinus rhythm except for the rate, which will be below 60 in sinus bradycardia. The P waves will be shaped differently in other dysrhythmias. The QRS is the same voltage for sinus rhythms. The P-R interval is prolonged in atrioventricular blocks.

The client asks the nurse to explain what is meant by a ventricular bigeminy cardiac rhythm. What is the best response by the nurse?

"The rhythm has a normal beat, then a premature beat pattern."- Bigeminy is a rhythm in which every other complex is a premature ventricular contraction (PVC). In trigeminy, every third complex is a PVC. The rhythm is not regular and the rate should not be 150-250 bpm.

A client with a second-degree atrioventricular heart block, Type II is admitted to the coronary care unit. How will the nurse explain the need to monitor the client's electrocardiogram (ECG) strip to the spouse?

"The small box will transmit the heart rhythm to the central monitor all the time."-In telemetry, a small box transmits the client's heart rhythm to the central unit for constant monitoring. Telemetry has nothing to do with the client needing help. A Holter monitor is a device that records the heart's electrical activity and for later review by a physician. The telemetry transmits the heart rhythm regardless of the client's heart rate.

The nursing student asks the nurse how to tell the difference between ventricular tachycardia and ventricular fibrillation on an electrocardiogram strip. What is the best response?

"Ventricular fibrillation is irregular with undulating waves and no QRS complex. Ventricular tachycardia is usually regular and fast, with wide QRS complexes."- Ventricular fibrillation is irregular with undulating waves and no QRS complex, while ventricular tachycardia is usually regular and fast with wide QRS complexes. The rhythms look different on the electrocardiogram strip. The QRS is wide and bizarre or undefined in ventricular fibrillation. The P-R interval is not present in the ventricular dysrhythmias.

The nurse is caring for a client who had a permanent pacemaker surgically placed and is now ready for discharge. What statement made by the client indicates the need for more education?

"We will be getting rid of our microwave oven so it will not affect my pacemaker." -Permanent pacemaker generators have filters that protect them from electrical interference from most household devices, motors, and appliances, so the client can keep the microwave oven. Clients are taught to check pulses daily, avoid large magnets, and report any incisional redness or swelling.

The nurse is working with a client with a new onset of atrial fibrillation during a three-month follow-up visit. The healthcare provider is planning a cardioversion, and the client asks the nurse why there is a wait for the treatment. What is the best response by the nurse?

"Your atrial chambers may contain blood clots now, so you must take an anticoagulant for a few weeks before the cardioversion."- Because of the high risk of embolization of atrial thrombi, cardioversion of atrial fibrillation that has lasted longer than 48 hours should be avoided unless the client has received warfarin for at least 3 to 4 weeks prior to cardioversion. The doctor will not wait for a change in rhythm. Resting the heart will not change the rhythm. There is no delay but safer for the clots to be dissolved with the anticoagulant.

After performing an ECG on an adult client, the nurse reports that the PR interval reflects normal sinus rhythm. What is the PR interval for a normal sinus rhythm?

0.12 and 0.2 seconds.- The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex. It measures the time needed for conduction through the AV node before ventricular depolarization. The normal range in adults is 0.12 to 0.2 seconds.

A client is admitted to the emergency department reporting chest pain and shortness of breath. The nurse notes an irregular rhythm on the bedside electrocardiograph monitor. The nurse counts 9 RR intervals on the client's 6-second rhythm tracing. The nurse correctly identifies the client's heart rate as

90 bpm.- An alternative but less accurate method for estimating heart rate, which is usually used when the rhythm is irregular, is to count the number of RR intervals in 6 seconds and multiply that number by 10. The RR intervals are counted, rather than QRS complexes, because a computed heart rate based on the latter might be inaccurately high. The same methods may be used for determining atrial rate, using the PP interval instead of the RR interval. In this instance, 9 × 10 = 90.

The nurse is assigned the following client assignment on the clinical unit. For which client does the nurse anticipate cardioversion as a possible medical treatment?

A client with atrial dysrhythmias- The nurse is correct to identify a client with atrial dysrhythmias as a candidate for cardioversion. The goal of cardioversion is to restore the normal pacemaker of the heart, as well as, normal conduction. A client with a myocardial infarction has tissue damage. The client with poor perfusion has circulation problems. The client with heart block has an impairment in the conduction system and may require a pacemaker.

The licensed practical nurse is setting up the room for a client arriving at the emergency department with ventricular arrhythmias. The nurse is most correct to place which of the following in the room for treatment?

A defibrillator- The nurse is most correct to place a defibrillator close to the client room if not in the room. The nurse realizes that clients with ventricular dysrhythmias are at a high risk for fatal heart dysrhythmia and death. A suction machine is used to remove respiratory secretions. Cardioversion is used in a planned setting for atrial dysrhythmias. An ECG machine records tracings of the heart for diagnostic purposes. Most clients with history of cardiac disorders have an ECG completed.

Which of the following medication classifications is more likely to be expected when the nurse is caring for a client with atrial fibrillation?

Anticoagulant- Clients with persistent atrial fibrillation are prescribed anticoagulation therapy to reduce the risk of emboli formation associated with ineffective circulation. The other options may be prescribed but not expected in most situations.

A nurse provides evening care for a client wearing a continuous telemetry monitor. While the nurse is giving the client a back rub, the client 's monitor alarm sounds and the nurse notes a flat line on the bedside monitor system. What is the nurse's first response?

Assess the client and monitor leads.- The nurse should assess the client and monitor leads first. It is important that the nurse "treat the client, not the monitor." Ventricular asystole may often appear on the monitor when leads are displaced. The other interventions are not necessary.

The nurse cares for a client with a dysrhythmia and understands that the P wave on an electrocardiogram (ECG) represents which phase of the cardiac cycle?

Atrial depolarization- The P wave represents atrial depolarization. The QRS complex represents ventricular depolarization. The T wave represents ventricular repolarization. The ST segment represents early ventricular repolarization, and lasts from the end of the QRS complex to the beginning of the T wave.

A nurse is caring for a client who's experiencing sinus bradycardia with a pulse rate of 40 beats/minute. The client's blood pressure is 80/50 mm Hg and the client reports dizziness. Which medication does the nurse anticipate administering to treat bradycardia?

Atropine-I.V. push atropine is used to treat symptomatic bradycardia. Dobutamine is used to treat heart failure and low cardiac output. Amiodarone is used to treat ventricular fibrillation and unstable ventricular tachycardia. Lidocaine is used to treat ventricular ectopy, ventricular tachycardia, and ventricular fibrillation.

A client presents to the emergency department via ambulance with a heart rate of 210 beats/minute and a sawtooth waveform pattern per cardiac monitor. The nurse is most correct to alert the medical team of the presence of a client with which disorder?

Atrial flutter- Atrial flutter is a disorder in which a single atrial impulse outside the SA node causes the atria to contract at an exceedingly rapid rate. The atrioventricular (AV) node conducts only some impulses to the ventricle, resulting in a ventricular rate slower than the atrial rate, thus forming a sawtooth pattern on the heart monitor. Asystole is the absence of cardiac function and can indicate death. Premature ventricular contraction indicates an early electric impulse and does not necessarily produce an exceedingly rapid heart rate. Ventricular fibrillation is the inefficient quivering of the ventricles and indicative of a dying heart.

The nurse is providing discharge instructions to a client after a permanent pacemaker insertion. Which safety precaution will the nurse communicate to the client?

Avoid undergoing magnetic resonance imaging (MRI).- A client with a pacemaker should avoid undergoing an MRI because the magnet could disrupt pacemaker function and cause injury to the client. Disruption is less likely to occur with newer microwave ovens. The client must avoid vigorous arm and shoulder movement only for the first 6 weeks after pacemaker implantation. Airport metal detectors don't harm pacemakers; however, the client should notify airport security guards that he has a pacemaker because its metal casing and programming magnet could trigger the metal detector.

A nurse provides morning care for a client in the intensive care unit (ICU). Suddenly, the bedside monitor shows ventricular fibrillation and the client becomes unresponsive. After calling for assistance, what action should the nurse take next?

Begin cardiopulmonary resuscitation- In the acute care setting, when ventricular fibrillation is noted, the nurse should call for assistance and defibrillate the client as soon as possible. If defibrillation is not readily available, CPR is begun until the client can be defibrillated, followed by advanced cardiovascular life support (ACLS) intervention, which includes endotracheal intubation and administration of epinephrine. Electrical cardioversion is not indicated for a client in ventricular fibrillation.

The nurse is observing the monitor of a patient with a first-degree atrioventricular (AV) block. What is the nurse aware characterizes this block?

Delayed conduction, producing a prolonged PR interval- First-degree AV block occurs when all the atrial impulses are conducted through the AV node into the ventricles at a rate slower than normal. Thus the PR interval is prolonged (>0.20 seconds).

A nurse is caring for a client who has been admitted to have a cardioverter defibrillator implanted. The nurse knows that implanted cardioverter defibrillators are used in which clients?

Clients with recurrent life-threatening tachydysrhythmias- The automatic implanted cardioverter defibrillator (AICD) is an internal electrical device used for selected clients with recurrent life-threatening tachydysrhythmias. Therefore, options A, B, and C are incorrect.

The nurse knows that a pacemaker is the treatment of choice for what cardiac dysrhythmia?

Complete heart block-Pacemaker insertion is the treatment for complete heart block. Treatments for supraventricular tachycardia are: Valsalva maneuver, unilateral carotid massage, immersion of face in ice water, administration of IV adenosine, cardioversion, and radiofrequency ablation. Cardioversion and drug therapy are used for the treatment of atrial flutter. Treatment for ventricular fibrillation is defibrillation preceded by or followed with epinephrine.

The nurse is assessing a patient with a probable diagnosis of first-degree AV block. The nurse is aware that this dysrhythmia is evident on an ECG strip by what indication?

Delayed conduction, producing a prolonged PR interval- First-degree AV block may occur without an underlying pathophysiology, or it can result from medications or conditions that increase parasympathetic tone. It occurs when atrial conduction is delayed through the AV node, resulting in a prolonged PR interval.

After evaluating a client for hypertension, a health care provider orders atenolol, 50 mg P.O. daily. Which therapeutic effect should atenolol have in treating hypertension?

Decreased cardiac output and decreased systolic and diastolic blood pressure- As a long-acting, selective beta1-adrenergic blocker, atenolol decreases cardiac output and systolic and diastolic blood pressure; however, like other beta-adrenergic blockers, it increases peripheral vascular resistance at rest and with exercise. Atenolol may cause bradycardia, not tachycardia.

The nurse analyzes the electrocardiogram (ECG) strip of a stable patient admitted to the telemetry unit. The client's ECG strip demonstrates PR intervals that measure 0.24 seconds. What is the nurse's most appropriate action?

Document the findings and continue to monitor the patient- The client's electrocardiogram (ECG) tracing indicates a first-degree atrioventricular (AV) block. First-degree AV block rarely causes any hemodynamic effect; the other blocks may result in decreased heart rate, causing a decrease in perfusion to vital organs, such as the brain, heart, kidneys, lungs, and skin. The most appropriate action by the nurse is to document the findings and continue to monitor the client.

A client has been living with an internal, fixed-rate pacemaker. When checking the client's readings on a cardiac monitor the nurse notices an absence of spikes. What should the nurse do?

Double-check the monitoring equipment.- One of the reasons for lack of pacemaker spikes is faulty monitoring equipment.

The nurse is caring for a client with atrial fibrillation. What procedure would be recommended if drug therapies did not control the dysrhythmia?

Elective cardioversion- Atrial fibrillation also is treated with elective cardioversion or digitalis if the ventricular rate is not too slow. Defibrillation is used for a ventricular problem. A Maze procedure is only a distractor for this question. Pacemakers are implanted for bradycardia.

Which diagnostic study best evaluates different medications ability to restore normal heart rhythm?

Electrophysiology study- An electrophysiology study is a procedure that enables the physician to examine the electrical activity of the heart, produce actual dysrhythmias, and determine the best method for care. Cardioversion uses synchronized electricity to change the rhythm pattern. Electrocardiogram and echocardiograms provide diagnostic information.

The nurse is caring for a client who has premature ventricular contractions. What sign or symptom is observed in this client?

Fluttering- Premature ventricular contractions usually cause a flip-flop sensation in the chest, sometimes described as "fluttering." Associated signs and symptoms include pallor, nervousness, sweating, and faintness. Symptoms of premature ventricular contractions are not nausea, hypotension, and fever.

The nurse reads an athletic client's electrocardiogram. What finding will be consistent with a sinus bradycardia?

Heart rate of 42 beats per minute (bpm).-The heart rate of 42 bpm is slow but normal when it occurs in athletes with a sinus bradycardia. The PR interval is prolonged at 0.24 seconds, indicating a heart block. The QR interval is prolonged and indicates ventricular delay. The ratio of P to QR should be 1:1 in sinus bradycardia.

The nurse identifies which of the following as a potential cause of premature ventricular complexes (PVCs)?

Hypokalemia-PVCs can be caused by cardiac ischemia or infarction, increased workload on the heart (e.g., exercise, fever, hypervolemia, heart failure, tachycardia), digitalis toxicity, acidosis, or electrolyte imbalances, especially hypokalemia.

The nurse enters the client's room and finds the client pulseless and unresponsive. What would be the treatment of choice for this client?

Immediate defibrillation- Defibrillation is used during pulseless ventricular tachycardia and ventricular fibrillation.

A client is treated in the intensive care unit (ICU) following an acute myocardial infarction (MI). During the nursing assessment, the client reports shortness of breath and chest pain. In addition, the client's blood pressure (BP) is 100/60 mm Hg with a heart rate (HR) of 53 bpm, and the electrocardiogram (ECG) tracing shows more P waves than QRS complexes. Which action should the nurse complete first?

Initiate transcutaneous pacing- The client is experiencing a third-degree heart block. Transcutaneous pacing should be implemented first. A permanent pacemaker may be indicated if the block continues. Defibrillation is not indicated; third-degree heart block does not respond to atropine; a 12-lead ECG may be obtained, but is not completed first.

The staff educator is teaching a class in dysrhythmias. What statement is correct for defibrillation?

It is used to eliminate ventricular dysrhythmias.- The only treatment for a life-threatening ventricular dysrhythmia is immediate defibrillation, which has the exact same effect as cardioversion, except that defibrillation is used when there is no functional ventricular contraction. It is an emergency procedure performed during resuscitation. The client is not sedated but is unresponsive. Defibrillation uses more electrical energy (200 to 360 joules) than cardioversion.

The nurse is caring for a client who has a suspected dysrhythmia. What most appropriate intervention should the nurse use to help detect dysrhythmias?

Monitor cardiac rhythm continuously.- The nurse should monitor cardiac rhythm continuously. Cardiac monitors display real-time heart rate and rhythm and alert the nurse to potentially life-threatening dysrhythmias. Monitoring blood pressure continuously and palpating the client's pulse do not help detect life-threatening dysrhythmias. Providing supplemental oxygen helps maintain adequate cardiac output and does not help detect life-threatening dysrhythmias.

To evaluate a client's atrial depolarization, the nurse observes which part of the electrocardiogram waveform?

P wave- The P wave depicts atrial depolarization, or spread of the electrical impulse from the sinoatrial node through the atria. The PR interval represents spread of the impulse through the interatrial and internodal fibers, atrioventricular node, bundle of His, and Purkinje fibers. The QRS complex represents ventricular depolarization. The T wave depicts the relative refractory period, representing ventricular repolarization.

The nurse is assessing vital signs in a patient with a permanent pacemaker. What should the nurse document about the pacemaker?

Pacer rate- After a permanent pacemaker is inserted, the patient's heart rate and rhythm are monitored by ECG.

Which term is used to describe a tachycardia characterized by abrupt onset, abrupt cessation, and a QRS of normal duration?

Paroxysmal atrial tachycardia- Paroxysmal atrial tachycardia (PAT) is often caused by a conduction problem in the AV node and is now called AV nodal reentry tachycardia. Sinus tachycardia occurs when the sinus node regularly creates an impulse at a faster-than-normal rate. Atrial flutter occurs in the atrium and creates an atrial rate between 250 to 400 times per minute. Atrial fibrillation causes a rapid, disorganized, and uncoordinated twitching of atrial musculature.

A healthy adult client is seeing a health care provider for an annual physical examination. While the nurse is taking the client's vital signs, the client states, "Occasionally, my heart skips a beat. Is this normal?" What is the nurse's best response?

Premature atrial complex- A premature atrial complex (PAC) is a single ECG complex that occurs when an electrical impulse starts in the atrium before the next normal impulse of the sinus node.

Which ECG waveform characterizes conduction of an electrical impulse through the left ventricle?

QRS complex- The QRS complex represents ventricular depolarization. The P wave is an ECG characteristic reflecting conduction of an electrical impulse through the atria. The PR interval is a component of an ECG tracing reflecting conduction of an electrical impulse through the AV node. The QT interval is an ECG characteristic reflecting the time from ventricular depolarization to repolarization.

The nurse analyzes the electrocardiogram (ECG) tracing of a client newly admitted to the cardiac step-down unit with a diagnosis of chest pain. Which finding indicates the need for follow-up?

QT interval that is 0. 46 seconds long- The QT interval that is 0.46 seconds long needs to be investigated. The QT interval is usually 0.32 to 0.40 seconds in duration if the heart rate is 65 to 95 bpm. If the QT interval becomes prolonged, the client may be at risk for a lethal ventricular dysrhythmia, called torsades de pointes. The other findings are normal.

The nurse is placing electrodes for a 12-lead electrocardiogram (ECG). The nurse would be correct in placing an electrode on which area for V1?

Right side of sternum, fourth intercostal space

The staff educator is presenting a class on cardiac dysrhythmias. How would the educator describe the characteristic pattern of the atrial waves in atrial flutter?

Sawtooth- Sawtooth is the characteristic pattern of the atrial waves in atrial flutter.

An operating room nurse is caring for a client who is having a pacemaker implanted. The health care provider has requested a demand mode pacemaker for this client. What is this type of pacemaker?

Self-activated- Demand (synchronous) mode pacemakers self-activate when the client's pulse falls below a certain level. A fixed-rate pacemaker is asynchronous and permanent. Temporary pacemakers are used until a permanent pacemaker can be implanted.

A client has been diagnosed with atrial fibrillation and has been prescribed warfarin therapy. What should the nurse prioritize when providing health education to the client?

The need to have regular blood levels drawn-One drawback of warfarin therapy is the need to have blood levels drawn on a regular basis. The medication does not need to be taken on an empty stomach, and the client does not have to sit upright. Adequate fluid intake is useful in a general way, but the need for fluids is not increased by taking warfarin.

The licensed practical nurse is co-assigned with a registered nurse in the care of a client admitted to the cardiac unit with chest pain. The licensed practical nurse is assessing the accuracy of the cardiac monitor, which notes a heart rate of 34 beats/minute. The client appears anxious and states not feeling well. The licensed practical nurse confirms the monitor reading. When consulting with the registered nurse, which of the following is anticipated?

The registered nurse administering atropine sulfate intravenously- The licensed practical nurse and registered nurse both identify that client's bradycardia. Atropine sulfate, a cholinergic blocking agent, is given intravenously (IV) to increase a dangerously slow heart rate. Lanoxin is not administered when the pulse rate falls under 60 beats/minute. It is dangerous to wait until the pulse rate increases without nursing intervention or administering additional medications until the imminent concern is addressed.

A patient who had a myocardial infarction is experiencing severe chest pain and alerts the nurse. The nurse begins the assessment but suddenly the patient becomes unresponsive, no pulse, with the monitor showing a rapid, disorganized ventricular rhythm. What does the nurse interpret this rhythm to be?

Ventricular fibrillation- The most common dysrhythmia in patients with cardiac arrest is ventricular fibrillation, which is a rapid, disorganized ventricular rhythm that causes ineffective quivering of the ventricles. No atrial activity is seen on the ECG. The most common cause of ventricular fibrillation is coronary artery disease and resulting acute myocardial infarction. Ventricular fibrillation is always characterized by the absence of an audible heartbeat, a palpable pulse, and respirations.

A patient with hypertension has a newly diagnosed atrial fibrillation. What medication does the nurse anticipate administering to prevent the complication of atrial thrombi?

Warfarin- Because atrial function may be impaired for several weeks after cardioversion, warfarin is indicated for at least 4 weeks after the procedure. Patients may be given amiodarone, flecainide, ibutilide, propafenone, or sotalol prior to cardioversion to enhance the success of cardioversion and prevent relapse of the atrial fibrillation (Fuster, Rydén et al., 2011).

The nurse is caring for a client who is displaying a third-degree AV block on the EKG monitor. What is the priority nursing intervention for the client?

alerting the healthcare provider of the third-degree heart block- The client may experience low cardiac output with third-degree AV block. The healthcare provider needs to intervene to preserve the client's cardiac output. Monitoring the blood pressure and heart rate are important, but not a priority. The identification of a code status during a heart block is not appropriate. IV fluids are not helpful if the heart is not perfusing.

The nurse is caring for a client with second-degree atrioventricular block, Type I with symptomatic bradycardia. What is the most likely medication the nurse will administer?

atropine sulfate-Atropine blocks acetylcholine at parasympathetic neuroeffector sites and blocks vagal stimulation. The client will be treated with an anticholinergic that blocks the effects of the vagal nerve. Atenolol and nadolol are beta blockers that are used for chest pain, myocardial infarction, and hypertension. Diltiazem is a calcium channel blocker used to treat angina or slow the heart rate.

The nurse is assessing a client with symptomatic bradycardia. What medication does the nurse anticipate will be ordered by the healthcare provider to treat the bradycardia?

atropine-The treatment of symptomatic bradycardia includes transcutaneous pacing and atropine. Lidocaine may be used in the treatment of ventricular fibrillation. Diltiazem and adenosine are medications used to treat clients with atrial fibrillation.

When the appropriate electrocardiogram (ECG) complex follows the pacing spike, it is said to be

captured.- Capture is a term used to denote that the appropriate electrocardiogram (ECG) complex followed by the pacing spike. Triggered response means that the pacemaker will respond when it senses intrinsic heart activity. Inhibited response means that the response of the pacemaker is controlled by the activity of the client's heart.

The nurse witnesses a client experiencing ventricular fibrillation. What is the nurse's priority action?

defibrillation- Advanced cardiac life support recommends early defibrillation for witnessed ventricular fibrillation. A cardioversion is used with a client who has a pulse. Atropine is used for bradycardia and dobutamine is an inotropic medication used to increased cardiac output.

A client reports light-headedness, chest pain, and shortness of breath. They physician orders tests to ascertain what is causing the client's problems. Which test is used to identify cardiac rhythms?

electrocardiogram- An electrocardiogram is used to identify normal and abnormal cardiac rhythms.

The nurse analyzes a 6-second electrocardiogram (ECG) tracing. The P waves and QRS complexes are regular. The PR interval is 0.18 seconds long, and the QRS complexes are 0.08 seconds long. The heart rate is calculated at 70 bpm. The nurse correctly identifies this rhythm as

normal sinus rhythm.- The electrocardiogram (ECG) tracing shows normal sinus rhythm (NSR). NSR has the following characteristics: ventricular and atrial rate: 60 to 100 beats per minute (bpm) in the adult; ventricular and atrial rhythm: regular; and QRS shape and duration: usually normal, but may be regularly abnormal; P wave: normal and consistent shape, always in front of the QRS; PR interval: consistent interval between 0.12 and 0.20 seconds and P:QRS ratio: 1:1.

The client returns to the clinic for a follow-up appointment following a permanent pacemaker insertion and reports tenderness and throbbing around the incision. The nurse observes mild swelling, erythema, and warmth at the pacemaker insertion site. What does the nurse suspect?

pacemaker site infection- Postoperative care for a pacemaker insertion includes observing for symptoms of infection. These symptoms include swelling, unusual tenderness, drainage, and increased warmth. When the site is healing normally, there will be no tenderness and throbbing. A hematoma forms a lump at the pacemaker insertion site. Mild bleeding will be drainage.

A client's Holter monitor strip reveals a heart rate with normal conduction but with a rate consistently above 105 beats/minute. What type of dysrhythmia would the cardiologist likely diagnose?

sinus tachycardia- Sinus tachycardia is a dysrhythmia that proceeds normally through the conduction pathway but at a faster than usual rate (100 to 150 beats/minute).