IBHRE Practice Exam 2 With 100% Correct Answers
1. What is the most likely consequence of prolonged QT interval on an ECG?
• A) Atrial flutter
• B) Torsades de Pointes
• C) Sinus bradycardia
• Answer: B) Torsades de Pointes
• Explanation: A prolonged QT interval predisposes patients to Torsades de Pointes, a type of
polymorphic ventricular tachycardia.
2. What is the primary use of atrial anti-tachycardia pacing (ATP) in ICDs?
• A) To pace atrial fibrillation
• B) To terminate atrial tachyarrhythmias
• C) To detect ventricular arrhythmias
• Answer: B) To terminate atrial tachyarrhythmias
• Explanation: Atrial ATP delivers rapid bursts of pacing to disrupt atrial tachyarrhythmias and
restore sinus rhythm.
3. Which part of the conduction system conducts impulses most rapidly?
• A) AV node
• B) SA node
• C) Purkinje fibers
• Answer: C) Purkinje fibers
• Explanation: Purkinje fibers rapidly conduct impulses through the ventricles, enabling quick and
efficient ventricular contraction.
4. What does the term “ventricular blanking period” in pacemaker terminology
refer to?
• A) A period of increased ventricular sensitivity
• B) A period when sensing is turned off
• C) The time between atrial and ventricular contractions
• Answer: B) A period when sensing is turned off
• Explanation: The ventricular blanking period is a period post-ventricular pacing when the device
ignores signals to prevent sensing of its own pacing output.
5. What is the purpose of the PVARP (post-ventricular atrial refractory period)
in pacemakers?
• A) To prevent sensing of retrograde P waves
, • B) To improve ventricular capture
• C) To reduce atrial pacing thresholds
• Answer: A) To prevent sensing of retrograde P waves
• Explanation: PVARP prevents the pacemaker from mistaking retrograde P waves as native atrial
events, avoiding inappropriate pacing.
6. Which device parameter would most likely be adjusted to prevent pacemaker-
mediated tachycardia (PMT)?
• A) Atrial lead sensitivity
• B) PVARP
• C) Ventricular amplitude
• Answer: B) PVARP
• Explanation: Extending the PVARP can help prevent PMT by reducing the chance of reentry
circuits involving retrograde P waves.
7. What is the purpose of an ICD's sensitivity setting?
• A) Determines how the device detects intrinsic cardiac events
• B) Adjusts the pacing voltage
• C) Determines the device's pacing rate
• Answer: A) Determines how the device detects intrinsic cardiac events
• Explanation: Sensitivity settings control how sensitive the device is to detecting intrinsic cardiac
signals to avoid inappropriate shocks or pacing.
8. Which arrhythmia is commonly treated with catheter ablation?
• A) Ventricular fibrillation
• B) Atrial fibrillation
• C) Sinus arrhythmia
• Answer: B) Atrial fibrillation
• Explanation: Catheter ablation can isolate the areas responsible for atrial fibrillation, potentially
reducing or eliminating episodes.
9. In a dual-chamber pacemaker, what does DDD pacing mode mean?
• A) Dual atrial and ventricular pacing and sensing with inhibition
• B) Dual atrial and ventricular pacing, sensing, and triggering
• C) Atrial pacing with ventricular sensing only
• Answer: B) Dual atrial and ventricular pacing, sensing, and triggering
• Explanation: DDD mode paces both chambers and triggers pacing based on sensed atrial or
ventricular events as needed.
10. What type of pacemaker response is characteristic of rate-adaptive
pacemakers?
1. What is the most likely consequence of prolonged QT interval on an ECG?
• A) Atrial flutter
• B) Torsades de Pointes
• C) Sinus bradycardia
• Answer: B) Torsades de Pointes
• Explanation: A prolonged QT interval predisposes patients to Torsades de Pointes, a type of
polymorphic ventricular tachycardia.
2. What is the primary use of atrial anti-tachycardia pacing (ATP) in ICDs?
• A) To pace atrial fibrillation
• B) To terminate atrial tachyarrhythmias
• C) To detect ventricular arrhythmias
• Answer: B) To terminate atrial tachyarrhythmias
• Explanation: Atrial ATP delivers rapid bursts of pacing to disrupt atrial tachyarrhythmias and
restore sinus rhythm.
3. Which part of the conduction system conducts impulses most rapidly?
• A) AV node
• B) SA node
• C) Purkinje fibers
• Answer: C) Purkinje fibers
• Explanation: Purkinje fibers rapidly conduct impulses through the ventricles, enabling quick and
efficient ventricular contraction.
4. What does the term “ventricular blanking period” in pacemaker terminology
refer to?
• A) A period of increased ventricular sensitivity
• B) A period when sensing is turned off
• C) The time between atrial and ventricular contractions
• Answer: B) A period when sensing is turned off
• Explanation: The ventricular blanking period is a period post-ventricular pacing when the device
ignores signals to prevent sensing of its own pacing output.
5. What is the purpose of the PVARP (post-ventricular atrial refractory period)
in pacemakers?
• A) To prevent sensing of retrograde P waves
, • B) To improve ventricular capture
• C) To reduce atrial pacing thresholds
• Answer: A) To prevent sensing of retrograde P waves
• Explanation: PVARP prevents the pacemaker from mistaking retrograde P waves as native atrial
events, avoiding inappropriate pacing.
6. Which device parameter would most likely be adjusted to prevent pacemaker-
mediated tachycardia (PMT)?
• A) Atrial lead sensitivity
• B) PVARP
• C) Ventricular amplitude
• Answer: B) PVARP
• Explanation: Extending the PVARP can help prevent PMT by reducing the chance of reentry
circuits involving retrograde P waves.
7. What is the purpose of an ICD's sensitivity setting?
• A) Determines how the device detects intrinsic cardiac events
• B) Adjusts the pacing voltage
• C) Determines the device's pacing rate
• Answer: A) Determines how the device detects intrinsic cardiac events
• Explanation: Sensitivity settings control how sensitive the device is to detecting intrinsic cardiac
signals to avoid inappropriate shocks or pacing.
8. Which arrhythmia is commonly treated with catheter ablation?
• A) Ventricular fibrillation
• B) Atrial fibrillation
• C) Sinus arrhythmia
• Answer: B) Atrial fibrillation
• Explanation: Catheter ablation can isolate the areas responsible for atrial fibrillation, potentially
reducing or eliminating episodes.
9. In a dual-chamber pacemaker, what does DDD pacing mode mean?
• A) Dual atrial and ventricular pacing and sensing with inhibition
• B) Dual atrial and ventricular pacing, sensing, and triggering
• C) Atrial pacing with ventricular sensing only
• Answer: B) Dual atrial and ventricular pacing, sensing, and triggering
• Explanation: DDD mode paces both chambers and triggers pacing based on sensed atrial or
ventricular events as needed.
10. What type of pacemaker response is characteristic of rate-adaptive
pacemakers?
