Dysrhythmias

12. A patient with myocardial infarction develops symptomatic hypotension. The monitor shows a type 1, second-degree AV block with a heart rate of 30. The nurse administers IV atropine as prescribed. The nurse determines that the drug has been effective on finding a(n) a. increase in the patient's heart rate. b. increase in peripheral pulse volume. c. decrease in ventricular response. d. decrease in premature contractions.

Correct Answer: A Rationale: Atropine will increase the heart rate and conduction through the AV node. Because the medication increases electrical conduction, not cardiac contractility, the quality of the peripheral pulses is not used to evaluate the drug effectiveness. Ventricular response will be increased by atropine because of the improvement in AV conduction. Atropine will not decrease PVCs, and the patient does not have PVCs.

18. A patient has received instruction on the management of a new permanent pacemaker before discharge from the hospital. The nurse recognizes that teaching has been effective when the patient tells the nurse, a. "I won't lift the arm on the pacemaker side up very high until I see the doctor." b. "I will notify the airlines when I make a reservation that I have a pacemaker." c. "I must avoid cooking with a microwave oven or being near a microwave in use." d. "It will be 6 weeks before I can take a bath or return to my usual activities."

Correct Answer: A Rationale: The patient is instructed to avoid lifting the arm on the pacemaker side above the shoulder to avoid displacing the pacemaker leads. The pacemaker rarely sets off an airport security alarm and there is no need to notify the airlines when making a reservation. Microwave oven use does not affect the pacemaker. The insertion procedure involves minor surgery that will have a short recovery period.

14. The nurse hears the cardiac monitor alarm and notes that the patient has a cardiac pattern of undulations of varying contours and amplitude with no measurable ECG pattern. The patient is unconscious with no pulse or respirations. After calling for assistance, the nurse should a. start basic cardiopulmonary resuscitation (CPR). b. administer an IV bolus dose of epinephrine. c. prepare the patient for endotracheal intubation. d. wait for the defibrillator to arrive.

Correct Answer: A Rationale: The patient's rhythm and assessment indicate ventricular fibrillation and cardiac arrest; therefore, the initial actions include calling for help, and initiating CPR until defibrillation is possible. If a defibrillator is not immediately available or is unsuccessful in converting the patient to a better rhythm, CPR should be continued and IV medications and endotracheal intubation should be initiated.

26. When analyzing the waveforms of a patient's ECG, the nurse will need to investigate further upon finding a a. PR interval of 0.18 second. b. QRS interval of 0.14 second. c. T wave of 0.16 second. d. QT interval of 0.34 second.

Correct Answer: B Rationale: Because the normal QRS interval is 0.04 to 0.10 seconds, the patient's QRS interval of 0.14 seconds indicates that the conduction through the ventricular conduction system is prolonged. The PR interval and QT interval are within the normal range. T-wave intervals are not measured when monitoring ECGs.

8. A patient has a normal cardiac rhythm strip except that the PR interval is 0.34 seconds. The appropriate intervention by the nurse is to a. prepare the patient for temporary pacemaker insertion. b. document the finding and continue to monitor the patient. c. notify the health care provider immediately. d. administer atropine per protocol.

Correct Answer: B Rationale: First-degree atrioventricular (AV) block is asymptomatic and requires ongoing monitoring because it may progress to more serious forms of heart block. The rate is normal, so there is no indication that atropine or a pacemaker is needed. Immediate notification of the health care provider about an asymptomatic rhythm is not necessary.

19. A patient who has a history of sudden cardiac death has an ICD inserted. When performing discharge teaching with the patient, it is important for the nurse to instruct the patient and family that a. medications will no longer be needed to control dysrhythmias. b. if the ICD fires and the patient loses consciousness, 911 should be called. c. CPR may displace the ICD leads and should not be performed. d. the ICD rarely triggers airport security alarms and travel without restrictions is allowed.

Correct Answer: B Rationale: If the ICD fires and the patient continues to have symptoms of cardiac arrest, activation of the emergency response system is indicated. The patient is likely to continue on medications to control dysrhythmias. If the patient experiences cardiac arrest, CPR should be performed. ICDs do trigger airport security alarms, and the patient will need to notify airport personnel about the presence of the device.

23. A 21-year-old college student arrives at the student health center at the end of the quarter complaining, "My heart is skipping beats." The nurse obtains an ECG and notes the presence of occasional PVCs. What action should the nurse take first? a. Ask the patient about any history of coronary artery disease. b. Question the patient about current stress level and coffee use. c. Have the patient transported to the hospital ED. d. Administer O2 to the patient at 2 to 3 L/min using nasal prongs.

Correct Answer: B Rationale: In a patient with a normal heart, occasional PVCs are a benign finding. The timing of the PVCs suggests stress or caffeine as possible etiologic factors. It is unlikely that the patient has coronary artery disease, and this should not be the first question the nurse asks. There is no indication that the patient needs to be seen in the ED or that oxygen needs to be administered.

24. A 19-year-old student has a mandatory ECG before participating on a college swim team and is found to have sinus bradycardia, rate 52. BP is 114/54, and the student denies any health problems. What action by the nurse is appropriate? a. Refer the student to a cardiologist for further assessment. b. Allow the student to participate on the swim team. c. Obtain more detailed information about the student's health history. d. Tell the student to stop swimming immediately if any dyspnea occurs.

Correct Answer: B Rationale: In an aerobically trained individual, sinus bradycardia is normal. The student's normal BP and negative health history indicate that there is no need for a cardiology referral or for more detailed information about the health history. Dyspnea during an aerobic activity such as swimming is normal.

1. In analyzing a patient's electrocardiographic (ECG) rhythm strip, the nurse uses the knowledge that the time of the conduction of an impulse through the Purkinje fibers is represented by the a. P wave. b. PR interval. c. QRS complex. d. QT interval.

Correct Answer: B Rationale: The PR interval represents depolarization of the atria, AV node, bundle of His, bundle branches, and the Purkinje fibers, up to the point of depolarization of the ventricular cells. The P wave represents atrial depolarization. The QRS represents ventricular depolarization. The QT interval represents depolarization of the depolarization and repolarization of the entire conduction system.

10. The nurse reviews data from the cardiac monitor indicating that a patient with a myocardial infarction experienced a 50-second episode of ventricular tachycardia before a sinus rhythm and a heart rate of 98 were re-established. The most appropriate initial action by the nurse is to a. notify the health care provider. b. administer IV antidysrhythmic drugs per protocol. c. defibrillate the patient. d. document the rhythm and continue to monitor the patient.

Correct Answer: B Rationale: The burst of sustained ventricular tachycardia indicates that the patient has significant ventricular irritability, and antidysrhythmic medication administration is needed to prevent further episodes. The nurse should notify the health care provider after the medications are administered. Defibrillation is not indicated given that the patient is currently in a sinus rhythm. Documentation and continued monitoring are not adequate responses to this situation.

22. A patient develops sinus bradycardia at a rate of 32 beats/min, has a BP of 80/36 mm Hg, and is complaining of feeling faint. Which action should the nurse take? a. Continue to monitor the rhythm and BP. b. Obtain and apply the transcutaneous pacemaker (TCP). c. Give the scheduled dose of diltiazem (Cardizem). d. Have the patient perform the Valsalva maneuver.

Correct Answer: B Rationale: The patient is experiencing symptomatic bradycardia and treatment with TCP is appropriate. Continued monitoring of the rhythm and BP is an inadequate response. Calcium-channel blockers will further decrease the heart rate, and the diltiazem should be held. The Valsalva maneuver will further decrease the rate.

7. The nurse determines that a patient has ventricular bigeminy when the rhythm strip indicates that a. there are pairs of wide and distorted QRS complexes. b. every other QRS complex is wide and starts prematurely. c. all QRS complexes are wide and the rate is 150 to 250 beats/min. d. there are premature QRS complexes with two different shapes.

Correct Answer: B Rationale: Ventricular bigeminy describes a rhythm in which every other QRS complex is wide and bizarre looking. Pairs of wide QRS complexes are described as couplets. Wide QRS complexes at a rate of 150 to 250 indicate ventricular tachycardia. Wide QRS complexes with different shapes are described as multifocal premature ventricular contractions (PVCs

3. A patient has a junctional escape rhythm on the monitor. The nurse would expect the patient to have a pulse rate of ____ beats/min. a. 15-20 b. 20-40 c. 40-60 d. 60-100

Correct Answer: C Rationale: If the SA node fails to discharge, the junction will automatically discharge at the normal junctional rate of 40 to 60. The slower rates are typical of the bundle of His and the Purkinje system and may be seen with failure of both the SA and AV node to discharge. The normal SA node rate is 60 to 100 beats/min.

15. During change-of-shift report, the nurse learns that a patient with a large myocardial infarction has been having frequent PVCs. When monitoring the patient for the effects of PVCs, the nurse will check the patient's a. medications. b. recent electrolyte values. c. apical radial heart rate. d. oxygen saturation.

Correct Answer: C Rationale: It is important to assess the patient's apical-radial pulse rate because PVCs often do not generate a sufficient ventricular contraction to result in a peripheral pulse, which can lead to a pulse deficit. Electrolyte imbalances, hypoxia, and certain medications may precipitate PVCs.

6. The nurse obtains a monitor strip on a patient admitted to the coronary care unit with a myocardial infarction and makes the following analysis: P wave not apparent; ventricular rate 162, R-R interval regular; PR interval not measurable; and QRS complex wide and distorted, QRS duration 0.18 second. The nurse interprets the patient's cardiac rhythm as a. sinus tachycardia. b. atrial fibrillation. c. ventricular tachycardia. d. ventricular fibrillation.

Correct Answer: C Rationale: The absence of P waves, wide QRS, rate >150, and the regularity of the rhythm indicate ventricular tachycardia. Atrial fibrillation is grossly irregular, has a narrow QRS configuration, and has fibrillatory P waves. Sinus tachycardia has P waves. Ventricular fibrillation is irregular and does not have a consistent QRS duration

21. A patient's sinus rhythm rate is 62. The PR interval is 0.18 seconds at 1:00 AM, 0.20 seconds at 12:30 PM, and 0.23 seconds at 4:00 PM. Which action should the nurse take? a. Document the patient's rhythm and continue to monitor. b. Prepare for possible pacemaker insertion. c. Hold the ordered metoprolol (Lopressor) and call the health care provider. d. Give the PRN dose of lidocaine (Xylocaine).

Correct Answer: C Rationale: The patient has progressive first-degree AV block, and the -blocker should be held until discussing the medication with the health care provider. Documentation and continued monitoring are not adequate responses because the block is progressively longer. The patient with first-degree AV block is asymptomatic, and a pacemaker is not indicated. Lidocaine is used to suppress ventricular dysrhythmias and is not appropriate to treat heart block.

16. A patient who has been successfully resuscitated after developing ventricular fibrillation asks the nurse about what happened. The most appropriate response by the nurse is, a. "You almost died, but we were able to save you with electrical therapy." b. "You had an episode of some cardiac dysrhythmias that are common after a heart attack." c. "You had a serious abnormal heart rhythm, which treatment was able to reverse." d. "Your heart stopped beating, and we shocked you to get it started again."

Correct Answer: C Rationale: This response honestly describes what happened to the patient while avoiding unnecessarily increasing the patient's anxiety level. More information may be given by the nurse if the patient asks further questions. The response "You had an episode of some cardiac dysrhythmias that are common after a heart attack" is not as honest and might lead to distrust of the nurse or health care system. The remaining two responses are accurate but would increase the anxiety level for many patients.

20. A patient with supraventricular tachycardia (SVT) is hemodynamically stable and requires cardioversion. The nurse will plan to a. turn the synchronizer switch to the "off" position. b. set the level of joules to 300 to convert the SVT. c. administer a sedative before the procedure is begun. d. check the incision for bleeding after the procedure.

Correct Answer: C Rationale: When a patient has a non-emergency cardioversion, sedation is used just before the procedure. The synchronizer switch is turned on for cardioversion. A low level of joules (e.g., 50) is first selected for cardioversion. There is no incision after cardioversion.

13. A patient with dilated cardiomyopathy has an atrial fibrillation that has been unresponsive to drug therapy for several days. The nurse anticipates that further treatment of the patient will require a. IV adenosine (Adenocard). b. electrical cardioversion. c. insertion of an implantable cardioverter-defibrillator (ICD). d. anticoagulant therapy with warfarin (Coumadin).

Correct Answer: D Rationale: Atrial fibrillation therapy that has persisted for more than 48 hours requires anticoagulant treatment for 3 to 4 weeks before attempting cardioversion; this is done to prevent embolization of clots from the atria. Adenosine is not used to treat atrial fibrillation. Cardioversion may be done after several weeks of Coumadin therapy. ICDs are used for patients with recurrent ventricular fibrillation.

9. A patient with diabetes mellitus is admitted unresponsive to the emergency department (ED). Initial laboratory findings are serum potassium 2.8 mEq/L (2.8 mmol/L), serum sodium 138 mEq/L (138 mmol/L), serum chloride 90 mEq/L (90 mmol/L), and blood glucose 628 mg/dl (34.9 mmol/L). Cardiac monitoring shows multifocal PVCs. The nurse understands that the patient's PVCs are most likely caused by a. hyperglycemia. b. hypoxemia. c. dehydration. d. hypokalemia.

Correct Answer: D Rationale: Hypokalemia increases the risk for ventricular dysrhythmias such as PVCs, ventricular tachycardia, and ventricular fibrillation. Hyperglycemia and dehydration are not associated with increased PVC risk. There is no indication that the patient is hypoxemic.

25. The nurse has received change-of-shift report about all of these patients on the telemetry unit. Which patient should the nurse see first? a. A patient with atrial fibrillation, rate 88, who has a new warfarin (Coumadin) order b. A patient with type 1 second-degree AV block, rate 60, who is dizzy when ambulating c. A patient who is in a sinus rhythm, rate 98, after having electrical cardioversion 2 hours ago d. A patient whose ICD fired three times today who is scheduled for a dose of amiodarone (Cordarone)

Correct Answer: D Rationale: The frequent firing of the ICD indicates that the patient's ventricles are very irritable, and the priority is to assess the patient and administer the amiodarone. The other patients may be seen after the amiodarone is administered.

17. A patient has a permanent pacemaker inserted for treatment of chronic atrial fibrillation with slow ventricular response. The nurse teaches the patient that the pacemaker will a. prevent or minimize ventricular irritability. b. discharge if ventricular fibrillation occurs and prevent cardiac arrest. c. depolarize the atria and generate a P wave. d. stimulate a heart beat if the patient's own heart rate drops too low.

Correct Answer: D Rationale: The permanent pacemaker will discharge when the ventricular rate drops below the set rate. The pacemaker will not decrease ventricular irritability or discharge if the patient develops ventricular fibrillation. A P wave will not be generated even with a dual-chamber pacemaker because the atria are already depolarizing in atrial fibrillation.

2. When needing to estimate the ventricular rate quickly for a patient with a regular heart rhythm using an ECG strip, the nurse will a. print a 1-minute ECG strip and count the number of QRS complexes. b. count the number of large squares in the R-R interval and divide by 300. c. calculate the number of small squares between one QRS complex and the next and divide into 1500. d. use the 3-second markers to count the number of QRS complexes in 6 seconds and multiply by 10.

Correct Answer: D Rationale: This is the quickest way to determine the ventricular rate for a patient with a regular rhythm. All the other methods take longer.