Heart block test 1
A patient in asystole is likely to receive which drug treatment? A. Epinephrine and atropine B. Lidocaine and amiodarone C. Digoxin and procainamide D. β-adrenergic blockers and dopamine
A. Normally the patient in asystole cannot be successfully resuscitated. However, administration of epinephrine and atropine may prompt the return of depolarization and ventricular contraction. Lidocaine and amiodarone are used for PVCs. Digoxin and procainamide are used for ventricular rate control. β-adrenergic blockers are used to slow heart rate, and dopamine is used to increase heart rate.
The nurse obtains a 6-second rhythm strip and charts the following analysis: Tab 1 Tab 2 Tab 3 Atrial data Ventricular data Additional data Rate: 70, regular Variable PR interval Independent beats Rate: 40, regular Isolated escape beats QRS: 0.04 sec P wave and QRS complexes unrelated What is the correct interpretation of this rhythm strip? A. Sinus arrhythmias B. Third-degree heart block C. Wenckebach phenomenon D. Premature ventricular contractions
B. Third-degree heart block represents a loss of communication between the atrium and ventricles from AV node dissociation. This is depicted on the rhythm strip as no relationship between the P waves (representing atrial contraction) and QRS complexes (representing ventricular contraction). The atria are beating totally on their own at 70 beats/min, whereas the ventricles are pacing themselves at 40 beats/min. Sinus dysrhythmia is seen with a slower heart rate with exhalation and an increased heart rate with inhalation. In Wenckebach heart block, there is a gradual lengthening of the PR interval until an atrial impulse is nonconducted and a QRS complex is blocked or missing. Premature ventricular contractions (PVCs) are the early occurrence of a wide, distorted QRS complex.
Which ECG characteristic is consistent with a diagnosis of ventricular tachycardia (VT)? A. Unmeasurable rate and rhythm B. Rate 150 beats/min; inverted P wave C. Rate 200 beats/min; P wave not visible D. Rate 125 beats/min; normal QRS complex
C. VT is associated with a rate of 150 to 250 beats/min; the P wave is not normally visible. Rate and rhythm are not measurable in ventricular fibrillation. P wave inversion and a normal QRS complex are not associated with VT.
A 38-year-old teacher who reported dizziness and shortness of breath while supervising recess is admitted with a dysrhythmia. Which medication, if ordered, requires the nurse to carefully monitor the patient for asystole? A. Atropine sulfate B. Digoxin (Lanoxin) C. Metoprolol (Lopressor) D. Adenosine (Adenocard)
D. IV adenosine (Adenocard) is the first drug of choice to convert supraventricular tachycardia to a normal sinus rhythm. Adenosine is administered IV rapidly (over 1 or 2 seconds) followed by a rapid, normal saline flush. The nurse should monitor the patient's ECG continuously because a brief period of asystole after adenosine administration is common and expected. Atropine sulfate increases heart rate, whereas lanoxin and metoprolol slow the heart rate.
A client is having frequent premature ventricular contractions. A nurse would place priority on assessment of which of the following items? 1. Blood pressure and peripheral perfusion 2. Sensation of palpitations 3. Causative factors such as caffeine 4. Precipitating factors such as infection
1. Premature ventricular contractions can cause hemodynamic compromise. The shortened ventricular filling time with the ectopic beats leads to decreased stroke volume and, if frequent enough, to decreased cardiac output. The client may be asymptomatic or may feel palpations. PVCs can be caused by cardiac disorders or by any number of physiological stressors, such as infection, illness, surgery, or trauma, and by the intake of caffeine, alcohol, or nicotine.
What criteria should the nurse use to determine normal sinus rhythm for a client on a cardiac monitor? Check all that apply. 1. The RR intervals are relatively consistent 2. One P wave precedes each QRS complex 3. Four to eight complexes occur in a 6 second strip 4. The ST segment is higher than the PR interval 5. The QRS complex ranges from 0.12 to 0.20 second.
1, 2. The consistency of the RR interval indicates regular rhythm. A normal P wave before each complex indicates the impulse originated in the SA node. The number of complexes in a 6 second strip is multiplied by 10 to approximate the heart rate; normal sinus rhythm is 60 to 100. Elevation of the ST segment is a sign of cardiac ischemia and is unrelated to the rhythm. The QRS duration should be less than 0.12 second; the PR interval should be 0.12 to 0.20 second.
A client has developed atrial fibrillation, which a ventricular rate of 150 beats per minute. A nurse assesses the client for: 1. Hypotension and dizziness 2. Nausea and vomiting 3. Hypertension and headache 4. Flat neck veins
1. The client with uncontrolled atrial fibrillation with a ventricular rate more than 150 beats a minute is at risk for low cardiac output because of loss of atrial kick. The nurse assesses the client for palpitations, chest pain or discomfort, hypotension, pulse deficit, fatigue, weakness, dizziness, syncope, shortness of breath, and distended neck veins.
A nurse is watching the cardiac monitor, and a client's rhythm suddenly changes. There are no P waves; instead there are wavy lines. The QRS complexes measure 0.08 second, but they are irregular, with a rate of 120 beats a minute. The nurse interprets this rhythm as: 1. Sinus tachycardia 2. Atrial fibrillation 3. Ventricular tachycardia 4. Ventricular fibrillation
2. Atrial fibrillation is characterized by a loss of P waves; an undulating, wavy baseline; QRS duration that is often within normal limits; and an irregular ventricular rate, which can range from 60 to 100 beats per minute (when controlled with medications) to 100 to 160 beats per minute (when uncontrolled).
A nurse is caring for a client with unstable ventricular tachycardia. The nurse instructs the client to do which of the following, if prescribed, during an episode of ventricular tachycardia? 1. Breathe deeply, regularly, and easily. 2. Inhale deeply and cough forcefully every 1 to 3 seconds. 3. Lie down flat in bed 4. Remove any metal jewelry
2. Cough cardiopulmonary resuscitation (CPR) sometimes is used in the client with unstable ventricular tachycardia. The nurse tells the client to use cough CPR, if prescribed, by inhaling deeply and coughing forcefully every 1 to 3 seconds. Cough CPR may terminate the dysrhythmia or sustain the cerebral and coronary circulation for a short time until other measures can be implemented.
While caring for a client who has sustained an MI, the nurse notes eight PVCs in one minute on the cardiac monitor. The client is receiving an IV infusion of D5W and oxygen at 2 L/minute. The nurse's first course of action should be to: 1. Increase the IV infusion rate 2. Notify the physician promptly 3. Increase the oxygen concentration 4. Administer a prescribed analgesic
2. PVCs are often a precursor of life-threatening dysrhythmias, including ventricular tachycardia and ventricular fibrillation. An occasional PVC is not considered dangerous, but if PVCs occur at a rate greater than 5 or 6 per minute in the post MI client, the physician should be notified immediately. More than 6 PVCs per minute is considered serious and usually calls for decreasing ventricular irritability by administering medications such as lidocaine. Increasing the IV infusion rate would not decrease the number of PVCs. Increasing the oxygen concentration should not be the nurse's first course of action; rather, the nurse should notify the physician promptly. Administering a prescribed analgesic would not decrease ventricular irritability.
A nurse is watching the cardiac monitor and notices that the rhythm suddenly changes. There are no P waves, the QRS complexes are wide, and the ventricular rate is regular but over 100. The nurse determines that the client is experiencing: 1. Premature ventricular contractions 2. Ventricular tachycardia 3. Ventricular fibrillation 4. Sinus tachycardia
2. Ventricular tachycardia is characterized by the absence of P waves, wide QRS complexes (usually greater than 0.14 second), and a rate between 100 and 250 impulses per minute. The rhythm is usually regular.
When auscultating the apical pulse of a client who has atrial fibrillation, the nurse would expect to hear a rhythm that is characterized by: 1. The presence of occasional coupled beats 2. Long pauses in an otherwise regular rhythm 3. A continuous and totally unpredictable irregularity 4. Slow but strong and regular beats
3. In atrial fibrillation, multiple ectopic foci stimulate the atria to contract. The AV node is unable to transmit all of these impulses to the ventricles, resulting in a pattern of highly irregular ventricular contractions.
The adaptations of a client with complete heart block would most likely include: 1. Nausea and vertigo 2. Flushing and slurred speech 3. Cephalalgia and blurred vision 4. Syncope and low ventricular rate
4. In complete atrioventricular block, the ventricles take over the pacemaker function in the heart but at a much slower rate than that of the SA node. As a result there is decreased cerebral circulation, causing syncope.
A patient has sought care following a syncopal episode of unknown etiology. Which nursing action should the nurse prioritize in the patient's subsequent diagnostic workup? A. Preparing to assist with a head-up tilt-test B. Preparing an IV dose of a β-adrenergic blocker C. Assessing the patient's knowledge of pacemakers D. Teaching the patient about the role of antiplatelet aggregators
A, In patients without structural heart disease, the head-up tilt-test is a common component of the diagnostic workup following episodes of syncope. IV β-blockers are not indicated although an IV infusion of low-dose isoproterenol may be started in an attempt to provoke a response if the head-up tilt-test did not have a response. Addressing pacemakers is premature and inappropriate at this stage of diagnosis. Patient teaching surrounding antiplatelet aggregators is not directly relevant to the patient's syncope at this time.
Which statement best describes the electrical activity of the heart represented by measuring the PR interval on the ECG? A. The length of time it takes to depolarize the atrium B. The length of time it takes for the atria to depolarize and repolarize C. The length of time for the electrical impulse to travel from the SA node to the Purkinje fibers D. The length of time it takes for the electrical impulse to travel from the SA node to the AV node
C. The electrical impulse in the heart must travel from the SA node through the AV node and into the Purkinje fibers in order for synchronous atrial and ventricular contraction to occur. When measuring the PR interval (the time from the beginning of the P wave to the beginning of the QRS), the nurse is identifying the length of time it takes for the electrical impulse to travel from the SA node to the Purkinje fibers. The P wave represents the length of time it takes for the impulse to travel from the SA node through the atrium causing depolarization of the atria (atrial contraction). Atrial repolarization occurs during ventricular depolarization and is hidden by the QRS complex. The length of time it takes for the electrical impulse to travel from the SA node to the AV node is the flat line between the end of the P wave and the beginning of the Q wave on the ECG and is not usually measured.
Cardioversion is attempted for a 64-year-old man with atrial flutter and a rapid ventricular response. After the nurse delivers 50 joules by synchronized cardioversion, the patient develops ventricular fibrillation. Which action should the nurse take immediately? A. Administer 250 mL of 0.9% saline solution IV by rapid bolus. B. Assess the apical pulse, blood pressure, and bilateral neck vein distention. C. Turn the synchronizer switch to the "off" position and recharge the device. D. Tell the patient to report any chest pain or discomfort and administer morphine sulfate.
C. Ventricular fibrillation produces no effective cardiac contractions or cardiac output. If during synchronized cardioversion the patient becomes pulseless or the rhythm deteriorates to ventricular fibrillation, the nurse should turn the synchronizer switch off and initiate defibrillation. Fluids, additional assessment, or treatment of pain alone will not restore an effective heart rhythm.
The nurse performs discharge teaching for a 74-year-old woman with an implantable cardioverter-defibrillator. Which statement by the patient indicates to the nurse that further teaching is needed? A. "The device may set off the metal detectors in an airport." B. "My family needs to keep up to date on how to perform CPR." C. "I should not stand next to antitheft devices at the exit of stores." D. "I can expect redness and swelling of the incision site for a few days."
D. Patients should be taught to report any signs of infection at incision site (e.g., redness, swelling, drainage) or fever to their primary care provider immediately. Teach the patient to inform airport security of presence of ICD because it may set off the metal detector. If hand-held screening wand is used, it should not be placed directly over the ICD. Teach the patient to avoid standing near antitheft devices in doorways of stores and public buildings, and to walk through them at a normal pace. Caregivers should learn cardiopulmonary resuscitation (CPR).
The nurse has obtained this rhythm strip from her patient's monitor: rate 110, normal PQRS. Which description of this ECG is correct? A. Sinus tachycardia B. Sinus bradycardia C. Ventricular fibrillation D. Ventricular tachycardia
This rhythm strip shows sinus tachycardia because the rate on this strip is above 101, and it displays normal P wave, PR interval, and QRS complex. Sinus bradycardia would look similar to sinus tachycardia but with a rate less than 60 beats per minute. Ventricular fibrillation does not have a measureable heart rate, PR interval, or QRS, and the P wave is not visible and the rhythm is irregular and chaotic. Ventricular tachycardia has a rate of 150 to 250 beats/minutes, with a regular or irregular rhythm and P waves occurring independently of the QRS complex.
A client with rapid rate atrial fibrillation asks a nurse why the physician is going to perform carotid massage. The nurse responds that this procedure may stimulate the: 1. Vagus nerve to slow the heart rate 2. Vagus nerve to increase the heart rate; overdriving the rhythm. 3. Diaphragmic nerve to slow the heart rate 4. Diaphragmic nerve to overdrive the rhythm
1. Carotid sinus massage is one of the maneuvers used for vagal stimulation to decrease a rapid heart rate and possibly terminate a tachydysrhythmia. The others include inducing the gag reflex and asking the client to strain or bear down. Medication therapy often is needed as an adjunct to keep the rate down or maintain the normal rhythm.
A nurse notices frequent artifact on the ECG monitor for a client whose leads are connected by cable to a console at the bedside. The nurse examines the client to determine the cause. Which of the following items is unlikely to be responsible for the artifact? 1. Frequent movement of the client 2. Tightly secured cable connections 3. Leads applied over hairy areas 4. Leads applied to the limbs
2. Tightly secured cable connections. Motion artifact, or "noise," can be caused by frequent client movement, electrode placement on limbs, and insufficient adhesion to the skin, such as placing electrodes over hairy areas of the skin. Electrode placement over bony prominence's also should be avoided. Signal interference can also occur with electrode removal and cable disconnection.
When ventricular fibrillation occurs in a CCU, the first person reaching the client should: 1. Administer oxygen 2. Defibrillate the client 3. Initiate CPR 4. Administer sodium bicarbonate intravenously
2. Ventricular fibrillation is a death-producing dysrhythmia and, once identified, must be terminated immediately by precordial shock (defibrillation). This is usually a standing physician's order in a CCU.
A nurse notes that a client with sinus rhythm has a premature ventricular contraction that falls on the T wave of the preceding beat. The client's rhythm suddenly changes to one with no P waves or definable QRS complexes. Instead there are coarse wavy lines of varying amplitude. The nurse assesses this rhythm to be: 1. Ventricular tachycardia 2. Ventricular fibrillation 3. Atrial fibrillation 4. Asystole
2. Ventricular fibrillation is characterized by irregular, chaotic undulations of varying amplitudes. Ventricular fibrillation has no measurable rate and no visible P waves or QRS complexes and results from electrical chaos in the ventricles.
A nurse is viewing the cardiac monitor in a client's room and notes that the client has just gone into ventricular tachycardia. The client is awake and alert and has good skin color. The nurse would prepare to do which of the following? 1. Immediately defibrillate 2. Prepare for pacemaker insertion 3. Administer amiodarone (Cordarone) intravenously 4. Administer epinephrine (Adrenaline) intravenously
3. First-line treatment of ventricular tachycardia in a client who is hemodynamically stable is the use of anti-dysrhythmics such as amiodarone (Cordarone), lidocaine (Xylocaine), and procainamide (Pronestyl). Cardioversion also may be needed to correct the rhythm (cardioversion is recommended for stable ventricular tachycardia). Defibrillation is used with pulseless ventricular tachycardia. Epinephrine would stimulate and already excitable ventricle and is contraindicated.
For which dysrhythmia is defibrillation primarily indicated? A. Ventricular fibrillation B. Third-degree AV block C. Uncontrolled atrial fibrillation D. Ventricular tachycardia with a pulse
A. Defibrillation is always indicated in the treatment of ventricular fibrillation. Drug treatments are normally used in the treatment of uncontrolled atrial fibrillation and for ventricular tachycardia with a pulse (if the patient is stable). Otherwise, synchronized cardioversion is used (as long as the patient has a pulse). Pacemakers are the treatment of choice for third-degree heart block.
The patient has hypokalemia, and the nurse obtains the following measurements on the rhythm strip: Heart rate of 86 with a regular rhythm; the P wave is 0.06 seconds (sec) and normal shape; the PR interval is 0.24 sec; the QRS is 0.09 sec. How should the nurse document this rhythm? A. First-degree AV block B. Second-degree AV block C. Premature atrial contraction (PAC) D. Premature ventricular contraction (PVC)
A. In first-degree AV block there is prolonged duration of AV conduction that lengthens the PR interval above 0.20 sec. In type I second-degree AV block the PR interval continues to increase in duration until a QRS complex is blocked. In Type II the PR interval may be normal or prolonged, the ventricular rhythm may be irregular, and the QRS is usually greater than 0.12 sec. PACs cause an irregular rhythm with a different-shaped P wave than the rest of the beats, and the PR interval may be shorter or longer. PVCs cause an irregular rhythm, and the QRS complex is wide and distorted in shape.
The nurse is watching the cardiac monitor, and a patient's rhythm suddenly changes. There are no P waves. Instead there are fine, wavy lines between the QRS complexes. The QRS complexes measure 0.08 sec (narrow), but they occur irregularly with a rate of 120 beats/min. The nurse correctly interprets this rhythm as what? A. Sinus tachycardia B. Atrial fibrillation C. Ventricular fibrillation D. Ventricular tachycardia
B. Atrial fibrillation is represented on the cardiac monitor by irregular R-R intervals and small fibrillatory (f) waves. There are no normal P waves because the atria are not truly contracting, just fibrillating. Sinus tachycardia is a sinus rate above 100 beats/minute with normal P waves. Ventricular fibrillation is seen on the ECG without a visible P wave; an unmeasurable heart rate, PR or QRS; and the rhythm is irregular and chaotic. Ventricular tachycardia is seen as three or more premature ventricular contractions (PVCs) that have distorted QRS complexes with regular or irregular rhythm, and the P wave is usually buried in the QRS complex without a measurable PR interval.
The patient has atrial fibrillation with a rapid ventricular response. The nurse knows to prepare for which treatment if an electrical treatment is planned for this patient? A. Defibrillation B. Synchronized cardioversion C. Automatic external defibrillator (AED) D. Implantable cardioverter-defibrillator (ICD)
B. Synchronized cardioversion is planned for a patient with supraventricular tachydysrhythmias (atrial fibrillation with a rapid ventricular response). Defibrillation or AEDs are the treatment of choice to end ventricular fibrillation and pulseless ventricular tachycardia (VT). An ICD is used with patients who have survived sudden cardiac death (SCD), have spontaneous sustained VT, and are at high risk for future life-threatening dysrhythmias.
The patient is admitted with acute coronary syndrome (ACS). The ECG shows ST-segment depression and T-wave inversion. What should the nurse know that this indicates? A. Myocardia injury B. Myocardial ischemia C. Myocardial infarction D. A pacemaker is present
B. The ST depression and T wave inversion on the ECG of a patient diagnosed with ACS indicate myocardial ischemia from inadequate supply of blood and oxygen to the heart. Myocardial injury is identified with ST-segment elevation. Myocardial infarction is identified with ST-segment elevation and a widened and deep Q wave. A pacemaker's presence is evident on the ECG by a spike leading to depolarization and contraction.
The nurse is doing discharge teaching with the patient and spouse of the patient who just received an implantable cardioverter-defibrillator (ICD) in the left side. Which statement by the patient indicates to the nurse that the patient needs more teaching? A. "I will call the cardiologist if my ICD fires." B. "I cannot fly because it will damage the ICD." C. "I cannot move my left arm until it is approved." D. "I cannot drive until my cardiologist says it is okay."
B. The patient statement that flying will damage the ICD indicates misunderstanding about flying. The patient should be taught that informing TSA about the ICD can be done because it may set off the metal detector and if a hand-held screening wand is used, it should not be placed directly over the ICD. The other options indicate the patient understands the teaching.
The nurse is caring for a patient who is 24 hours postpacemaker insertion. Which nursing intervention is most appropriate at this time? A. Reinforcing the pressure dressing as needed B. Encouraging range-of-motion exercises of the involved arm C. Assessing the incision for any redness, swelling, or discharge D. Applying wet-to-dry dressings every 4 hours to the insertion site
C. After pacemaker insertion, it is important for the nurse to observe signs of infection by assessing for any redness, swelling, or discharge from the incision site. The nonpressure dressing is kept dry until removed, usually 24 hours postoperatively. It is important for the patient to limit activity of the involved arm to minimize pacemaker lead displacement.
The nurse is seeing artifact on the telemetry monitor. Which factors could contribute to this artifact? A. Disabled automaticity B. Electrodes in the wrong lead C. Too much hair under the electrodes D. Stimulation of the vagus nerve fibers
C. Artifact is caused by muscle activity, electrical interference, or insecure leads and electrodes that could be caused by excessive chest wall hair. Disabled automaticity would cause an atrial dysrhythmia. Electrodes in the wrong lead will measure electricity in a different plane of the heart and may have a different wave form than expected. Stimulation of the vagus nerve fibers causes a decrease in heart rate, not artifact.
The nurse is monitoring the ECGs of several patients on a cardiac telemetry unit. The patients are directly visible to the nurse, and all of the patients are observed to be sitting up and talking with visitors. Which patient's rhythm would require the nurse to take immediate action? A. A 62-year-old man with a fever and sinus tachycardia with a rate of 110 beats/minute B. A 72-year-old woman with atrial fibrillation with 60 to 80 QRS complexes per minute C. A 52-year-old man with premature ventricular contractions (PVCs) at a rate of 12 per minute D. A 42-year-old woman with first-degree AV block and sinus bradycardia at a rate of 56 beats/minute
C. Frequent premature ventricular contractions (PVCs) (greater than 1 every 10 beats) may reduce the cardiac output and precipitate angina and heart failure, depending on their frequency. Because PVCs in CAD or acute MI indicate ventricular irritability, the patient's physiologic response to PVCs must be monitored. Frequent PVCs most likely must be treated with oxygen therapy, electrolyte replacement, or antidysrhythmic agents.
When computing a heart rate from the ECG tracing, the nurse counts 15 of the small blocks between the R waves of a patient whose rhythm is regular. From these data, the nurse calculates the patient's heart rate to be A. 60 beats/min. B. 75 beats/min. C. 100 beats/min. D. 150 beats/min.
C. Since each small block on the ECG paper represents 0.04 seconds, 1500 of these blocks represents 1 minute. By dividing the number of small blocks (15, in this case) into 1500, the nurse can calculate the heart rate in a patient whose rhythm is regular (in this case, 100).
A 50-year-old man who develops third-degree heart block reports feeling chest pressure and shortness of breath. Which instructions should the nurse provide to the patient before initiating emergency transcutaneous pacing? A. "The device will convert your heart rate and rhythm back to normal." B. "The device uses overdrive pacing to slow the heart to a normal rate." C. "The device is inserted through a large vein and threaded into your heart." D. "The device delivers a current through your skin that can be uncomfortable."
D. Before initiating transcutaneous pacing (TCP) therapy, it is important to tell the patient what to expect. The nurse should explain that the muscle contractions created by the pacemaker when the current passes through the chest wall are uncomfortable. Pacing for complete heart block will not convert the heart rhythm to normal. Overdrive pacing is used for very fast heart rates. Transcutaneous pacing is delivered through pacing pads adhered to the skin.
A nurse is assessing an electrocardiogram rhythm strip. The P waves and QRS complexes are regular. The PR interval is 0.16 second, and QRS complexes measure 0.06 second. The overall heart rate is 64 beats per minute. The nurse assesses the cardiac rhythm as: A. Normal sinus rhythm B. Sinus bradycardia C. Sick sinus syndrome D. First-degree heart block.
NORMAL SINUS RHYTHM 1. measurements are normal, measuring 0.12 to 0.20 second and 0.4 to 0.10 second, respectively.