Med Surg EKG/Cardiac Rhythms Quiz
Which clinical indicator is the nurse most likely to identify when completing a history and physical assessment of a client with complete heart block? Syncope Headache Tachycardia Hemiparesis
Answer: Syncope Rationale: With complete atrioventricular block, the ventricles take over the pacemaker function in the heart but at a much slower rate than that of the sinoatrial (SA) node. As a result, there is decreased cerebral circulation, causing syncope. Headache is not related to heart block. The heart rate usually is slow because the ventricular rhythm is not initiated by the SA node. Hemiparesis is associated with a brain attack (cerebrovascular accident).
The nurse notes that the client's cardiac rhythm strips show more P waves than QRS complexes. There is no relationship between the atria and the ventricles. How should the nurse interpret this rhythm strip? First degree atrioventricular (AV) block Second degree AV block Mobitz I (Wenckebach) Second degree AV block Mobitz II Third degree AV block (complete heart block)
Answer: Third degree AV block (complete heart block) Rationale: Third degree block often is 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 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. In first degree AV block, a P wave precedes every QRS complex, and every P wave is followed by a QRS. Second-degree AV block type I, also called Mobitz I or Wenckebach heart block, is represented on the ECG as a progressive lengthening of the PR interval until there is a P wave without a QRS complex. 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).
The nurse notes asystole on the cardiac monitor. Which action should the nurse take immediately? Defibrillate Assess the client's pulse Initiate advanced cardiac life support Check another lead to confirm asystole
Answer: Assess the client's pulse Rationale: Rationale Pulse should be immediately assessed because a lead or electrode coming off may mimic this dysrhythmia. Asystole is characterized by complete cessation of electrical activity. A flat baseline is seen, without any evidence of P, QRS, or T waveforms. A pulse is absent, and there is no cardiac output; cardiac arrest has occurred. Once confirmed, Basic Life Support (BLS) and Advanced Cardiovascular Life Support (ACLS) protocols are initiated for asystole. Defibrillation is part of the ACLS protocol for ventricular fibrillation.
A client is experiencing tachycardia. Which adverse hemodynamic effects will the nurse consider when planning care for this client? Select all that apply. Decreased ventricular filling time Increased coronary artery filling Decreased cardiac output Increased atrial kick Increased cardiac output
Answer: Decreased ventricular filling time Decreased cardiac output Rationale: Tachycardia is a fast heart rate; the fast heart rhythm may cause a decrease in cardiac output because of the decreased filling time for the ventricles. There is also a decreased, not increased, time for coronary artery filling during diastole. During atrial systole, a bolus of atrial blood is ejected into the ventricles; this step is called the atrial kick, and it contributes more blood to the cardiac output of the ventricles. With fast heart rates, there is less time for the atria to fill, and therefore less blood (atrial kick) to pump.
In addition to atrial fibrillation, which cardiac dysrhythmia exhibited by a client does the nurse determine may be converted to sinus rhythm by cardioversion? Cardiac standstill First degree heart block Supraventricular tachycardia Frequent premature complexes
Answer: Supraventricular tachycardia Rationale: Cardioversion involves administration of precordial shock, which is synchronized with the R wave to interrupt the heart rate. It is used for atrial fibrillation, supraventricular tachycardia, and ventricular tachycardia with a pulse when pharmaceutical preparations fail. The heart is stopped by the electrical stimulation, and it is hoped that the sinoatrial (SA) node will take over as pacemaker. Because there are no R waves in a cardiac standstill, defibrillation and not cardioversion should be done. Premature ventricular complexes suggest an irritable myocardium and generally respond to antidysrhythmic agents.
The client is in atrial fibrillation. Which information should the nurse consider about atrial fibrillation when planning care for this client? A loss of atrial kick No physiologic changes Increased cardiac output Decreased risk of pulmonary embolism
Answer: A loss of atrial kick Rationale: Atrial fibrillation arises from multiple ectopic foci in the atria, causing chaotic quivering of the atria and ineffectual atrial contraction. The atrioventricular (AV) node is bombarded with hundreds of atrial impulses and conducts these impulses in an unpredictable manner to the ventricles. This irregularity is called "irregularly irregular." 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. 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 client may or may not be aware of the atrial fibrillation. If the ventricular response is rapid, the client may show signs of decreased cardiac output or worsening of heart failure symptoms.
A client's cardiac monitor indicates ventricular tachycardia. The nurse assesses the client and identifies an increase in apical pulse rate from 100 to 150 beats per minute. What is an appropriate treatment plan? Amiodarone bolus Intracardiac epinephrine Insertion of a pacemaker Cardiopulmonary resuscitation (CPR)
Answer: Amiodarone bolus Rationale: Amiodarone suppresses ventricular activity; therefore, it is used for treatment of premature ventricular complexes (PVCs) and ventricular tachycardia. It works directly on the heart tissue and slows the nerve impulses in the heart. Epinephrine HCl is not used for ventricular tachycardia (VT) with a pulse; it is used for cardiac arrest and may even precipitate ventricular fibrillation. A pacemaker is used for symptomatic bradycardia and heart blocks. The client has a pulse; CPR is not indicated.
A nurse identifies premature ventricular complexes (PVCs) on a client's cardiac monitor. What does the nurse conclude that these complexes are a sign of? Atrial fibrillation Cardiac irritability Impending heart block Ventricular tachycardia
Answer: Cardiac irritability Rationale: Cardiac irritability is the cardinal reason for PVCs. Atrial fibrillation is a type of dysrhythmia, not the cause of PVCs; the source of atrial fibrillation is the atrium, not the ventricles. Impending heart block type of dysrhythmia is associated with interference with the conduction system. Ventricular tachycardia is a type of dysrhythmia, not the cause of PVCs.
A client is on a cardiac monitor. The monitor begins to alarm showing ventricular tachycardia. What should the nurse do first? Check for a pulse Start cardiac compressions Prepare to defibrillate the client Administer oxygen via an ambu bag
Answer: Check for a pulse Rationale: The treatment of ventricular tachycardia depends on the presence of a pulse. Therefore checking for a pulse is the first priority for the nurse. The nurse must rely on client assessment, not solely on the monitor. Cardiac compressions would not be initiated if there was a pulse. Administering oxygen via an ambu bag would only occur if the client was not breathing. The client is not automatically defibrillated. Cardioversion is recommended for slower ventricular tachycardia.
A client's diet is modified to eliminate foods that act as cardiac stimulants. Which foods will the nurse instruct the client to avoid? Select all that apply. Iced tea Red meat Club soda Hot cocoa Chocolate pudding
Answers: Iced tea Hot cocoa Chocolate pudding Rationale: Tea contains caffeine, which stimulates catecholamine release and acts as a cardiac stimulant; tea should be avoided. Hot cocoa contains chocolate, which contains caffeine; it stimulates catecholamine release and acts as a cardiac stimulant. Cocoa should be avoided. The chocolate in chocolate pudding has a high caffeine content, which may stimulate catecholamine release and act as a cardiac stimulant; chocolate should be avoided. Red meat does not stimulate the myocardium; however, it should be decreased or eliminated if serum cholesterol levels are elevated. Club soda does not contain caffeine and does not stimulate the myocardium; however, most club sodas contain sodium, which promotes fluid retention and should be avoided by a client with a cardiac condition.
What criteria should the nurse use to determine normal sinus rhythm for a client on a cardiac monitor? Select all that apply. The RR intervals are relatively consistent. One P wave precedes each QRS complex. The ST segment is higher than the PR interval. Four to eight complexes occur in a 6-second strip. The QRS complex ranges from 0.12 to 0.2 seconds.
Answers: The RR intervals are relatively consistent. One P wave precedes each QRS complex. Rationale: The consistency of the RR intervals indicates a regular rhythm. A normal P wave before each complex indicates the impulse originated in the sinoatrial (SA) node. Elevation of the ST segment is a sign of cardiac ischemia and unrelated to the rhythm. 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 beats/min. Fewer than six complexes per 6 seconds equals a heart rate less than 60 beats/min. The QRS duration should be less than 0.12 seconds; the PR interval should be 0.12 to 0.2 second.
