Cardiac Arrhythmia Management 2026 Nursing Protocols

Cardiac Arrhythmia Management: 2026 Nursing Protocols (Exam Prep) Question 1: A patient on the telemetry unit shows a heart rate of 42 bpm and is alert but pale. What is the nurse's priority action? A) Administer Atropine 1mg IV push. B) Prepare for immediate transcutaneous pacing. C) Assess the patient’s blood pressure and level of consciousness. D) Document the heart rate and continue routine monitoring. Correct Answer: C Rationale: In clinical judgment, hemodynamic stability must be assessed (BP and LOC) before any medical intervention. If the patient is stable, the nurse continues monitoring; if unstable, interventions like Atropine are required. Question 2: Which rhythm is characterized by a "saw-tooth" P-wave pattern on an ECG strip? A) Atrial Fibrillation B) Sinus Tachycardia C) Atrial Flutter D) Ventricular Fibrillation Correct Answer: C Rationale: Atrial flutter is distinct for its flutter waves (saw-tooth appearance) caused by a rapid atrial rate (typically 250-350 bpm) with a slower ventricular response. Question 3: A nurse notes a PR interval of 0.24 seconds on an ECG. How should this be interpreted? A) Normal sinus rhythm B) First-degree AV block C) Second-degree Type I block D) Third-degree AV block Correct Answer: B Rationale: A PR interval consistently greater than 0.20 seconds indicates a first-degree AV block, representing delayed conduction through the AV node. Question 4: In a patient experiencing Ventricular Fibrillation (V-Fib), what is the most critical first nursing action? A) Defibrillate the patient immediately if a defibrillator is in the room. B) Check the patient for a bounding pulse. C) Administer Epinephrine 1mg IV. D) Wait for the code team to arrive. Correct Answer: A Rationale: V-Fib is a lethal, shockable rhythm. According to 2026 ACLS guidelines, early defibrillation is the most effective intervention for survival, accompanied by high-quality CPR. Question 5: Which electrolyte imbalance is most likely to trigger dangerous cardiac arrhythmias, such as widened QRS complexes and peaked T-waves? A) Hypocalcemia B) Hypernatremia C) Hypochloremia D) Hyperkalemia Correct Answer: D Rationale: Hyperkalemia alters the resting membrane potential of cardiac cells, leading to peaked T-waves, prolonged PR intervals, and widened QRS complexes, which can progress to V-Fib. Question 6: A nurse notes "R-on-T" phenomenon on a monitor. Why is this clinically dangerous? A) It triggers symptomatic bradycardia. B) It indicates a benign wandering atrial pacemaker. C) It risks conversion to Ventricular Fibrillation. D) It is a normal physiological finding during sleep. Correct Answer: C Rationale: The "R-on-T" phenomenon occurs when a PVC falls on the vulnerable period of ventricular repolarization (the T-wave), which can precipitate lethal ventricular arrhythmias. Question 7: What is the primary nursing concern for a patient with chronic Atrial Fibrillation? A) Risk of severe hypertension. B) Risk of thromboembolic events such as a stroke. C) Risk of developing hypoglycemia. D) Risk of chronic pulmonary edema. Correct Answer: B Rationale: The quivering of the atria causes blood stasis, which promotes clot formation. If a clot dislodges, it can travel to the brain and cause an ischemic stroke. Question 8: During synchronized cardioversion for an unstable patient with SVT, the "sync" button must be: A) Turned OFF to deliver maximum energy. B) Turned ON to avoid shocking on the T-wave. C) Toggled intermittently during the procedure. D) Ignored as it only applies to defibrillation. Correct Answer: B Rationale: Synchronization ensures the electrical shock is delivered exactly on the R-wave of the QRS complex, avoiding the vulnerable T-wave and preventing iatrogenic Ventricular Fibrillation. Question 9: A "wide-complex" tachycardia is defined by a QRS duration of: A) Less than 0.10 seconds. B) Exactly 0.05 seconds. C) Greater than or equal to 0.12 seconds. D) Between 0.06 and 0.08 seconds. Correct Answer: C Rationale: A QRS duration of 0.12 seconds (3 small boxes) or greater indicates that the impulse originated in the ventricles or is being conducted aberrantly. Question 10: A paced rhythm shows spikes immediately before every P-wave and every QRS complex. This indicates: A) Ventricular pacing. B) Atrial pacing. C) Biventricular pacing. D) Dual-chamber pacing. Correct Answer: D Rationale: Dual-chamber pacemakers have leads in both the right atrium and right ventricle, producing a spike before atrial depolarization (P-wave) and ventricular depolarization (QRS). Question 11: What is the intrinsic firing rate of the AV node (Junctional Rhythm)? A) 20-40 bpm. B) 40-60 bpm. C) 60-100 bpm. D) 100-150 bpm. Correct Answer: B Rationale: If the SA node fails, the AV node acts as the secondary pacemaker, generating impulses at an intrinsic rate of 40 to 60 beats per minute. Question 12: If a patient's monitor shows Asystole, what is the nurse's priority action? A) Attempt to defibrillate at 200 Joules. B) Perform a vagal maneuver. C) Initiate immediate high-quality CPR. D) Administer Amiodarone. Correct Answer: C Rationale: Asystole is a non-shockable rhythm. The priority is to initiate chest compressions and administer Epinephrine according to ACLS protocols. Question 13: Torsades de Pointes is a polymorphic ventricular tachycardia most commonly associated with: A) Hypomagnesemia and a prolonged QT interval. B) Hypernatremia and a shortened PR interval. C) Hypoglycemia and inverted T-waves. D) Normal serum electrolytes and a narrow QRS. Correct Answer: A Rationale: Low magnesium levels prolong ventricular repolarization (long QT interval), predisposing the heart to this specific, twisting form of ventricular tachycardia. Question 14: Why is a Second-Degree Type II Heart Block (Mobitz II) clinically dangerous? A) It is usually completely asymptomatic. B) It has a high risk of sudden progression to complete (third-degree) heart block. C) It is a common, benign finding in athletes. D) It only occurs during deep sleep. Correct Answer: B Rationale: Mobitz II involves structural damage to the bundle branches and can rapidly deteriorate into a lethal complete heart block, often requiring a pacemaker. Question 15: Which morphology best describes a Premature Ventricular Contraction (PVC)? A) Narrow, uniform QRS complexes. B) Absent P-waves with a regular rate of 150 bpm. C) Wide, bizarre-looking QRS complexes occurring earlier than expected. D) A progressively lengthening PR interval. Correct Answer: C Rationale: Because PVCs originate in the ventricular tissue outside the normal conduction pathway, cell-to-cell depolarization is slower, resulting in a wide and bizarre QRS appearance. Question 16: Defibrillation energy delivery is described as: A) Synchronous. B) Asynchronous. C) Timed specifically to the R-wave. D) Dependent on the patient's breathing pattern. Correct Answer: B Rationale: Defibrillation delivers a massive, asynchronous shock to completely depolarize the myocardium simultaneously, allowing the SA node to reset the rhythm. Question 17: What is the primary clinical indication for Amiodarone in a code situation? A) To manage symptomatic bradycardia. B) To treat refractory Ventricular Fibrillation or pulseless Ventricular Tachycardia. C) To act as a first-line agent for Asystole. D) To maintain Normal Sinus Rhythm in healthy adults. Correct Answer: B Rationale: Amiodarone is a potent Class III anti-arrhythmic used in ACLS protocols for shock-refractory V-Fib and pulseless V-Tach. Question 18: What is the most important clinical consideration when administering Adenosine for SVT? A) Administer as a slow IV drip over 30 minutes. B) Monitor the patient for a permanent heart block. C) Ensure a rapid IV push followed by a rapid saline flush. D) Administer only through a central line. Correct Answer: C Rationale: Adenosine has an extremely short half-life (less than 10 seconds). It must be pushed rapidly and flushed immediately to reach the heart before metabolizing. Question 19: How often should the nursing team perform rhythm checks during CPR for a pulseless patient? A) Every 1 minute. B) Every 2 minutes. C) Every 5 minutes. D) Only when the provider arrives. Correct Answer: B Rationale: Standard 2026 ACLS guidelines require continuous CPR with brief pauses every 2 minutes for rhythm checks and compressor rotation. Question 20: If the telemetry monitor shows Ventricular Fibrillation, but the patient is sitting up in bed and talking, the nurse should first: A) Call a Code Blue. B) Retrieve the crash cart. C) Check the patient's lead placement for artifact. D) Administer Epinephrine. Correct Answer: C Rationale: You treat the patient, not the monitor. If the patient is alert and communicating, the lethal rhythm on the screen is an artifact (likely a loose lead or movement). Question 21: PEA (Pulseless Electrical Activity) is clinically identified when: A) The monitor shows no electrical activity and the patient has no pulse. B) The monitor shows an organized rhythm, but the patient has no palpable pulse. C) The monitor shows V-Fib and the patient has a weak pulse. D) The patient has a bounding pulse but no electrical activity on the monitor. Correct Answer: B Rationale: In PEA, the electrical conduction system is working (showing a rhythm), but the heart muscle is failing to contract or pump blood effectively. Question 22: On an ECG, a pacemaker "failure to capture" is visualized as: A) Pacing spikes followed immediately by wide QRS complexes. B) No pacing spikes present at all despite a low heart rate. C) Pacing spikes that are not followed by a QRS complex or P-wave. D) Pacing spikes falling on the T-wave. Correct Answer: C