IBHRE Practice Exam 3 With 100% Correct Answers
1. What is the primary purpose of biventricular pacing in CRT?
• A) To increase atrial contraction
• B) To synchronize left and right ventricular contraction
• C) To improve AV node conduction
• Answer: B) To synchronize left and right ventricular contraction
• Explanation: Biventricular pacing improves the timing between left and right ventricular
contractions, which can enhance cardiac output in heart failure patients.
2. What interval adjustment is most likely to prevent pacemaker-mediated
tachycardia (PMT)?
• A) Shortening the AV delay
• B) Extending the PVARP
• C) Increasing pacing amplitude
• Answer: B) Extending the PVARP
• Explanation: Extending the post-ventricular atrial refractory period (PVARP) prevents the
pacemaker from detecting retrograde P waves, which can trigger PMT.
3. In a single-chamber ICD, what does VVI mode mean?
• A) Senses and paces the atrium only
• B) Senses and paces the ventricle, inhibited by intrinsic ventricular activity
• C) Dual-chamber sensing with ventricular pacing
• Answer: B) Senses and paces the ventricle, inhibited by intrinsic ventricular activity
• Explanation: VVI mode paces the ventricle when it doesn’t detect intrinsic ventricular activity,
avoiding unnecessary pacing.
4. What is the most appropriate device therapy for symptomatic bradycardia due
to AV block?
• A) ICD
• B) CRT device
• C) Pacemaker
• Answer: C) Pacemaker
• Explanation: A pacemaker is used for AV block to ensure regular ventricular contraction when
the AV node is not conducting effectively.
5. What cardiac condition is the main reason for CRT-D therapy?
• A) Atrial fibrillation
• B) Left bundle branch block with heart failure
, • C) Atrial flutter
• Answer: B) Left bundle branch block with heart failure
• Explanation: CRT-D is used in heart failure patients with left bundle branch block, which can
worsen ventricular dyssynchrony.
6. Which arrhythmia often requires defibrillation rather than synchronized
cardioversion?
• A) Atrial flutter
• B) Ventricular fibrillation
• C) Sinus bradycardia
• Answer: B) Ventricular fibrillation
• Explanation: Ventricular fibrillation is a chaotic arrhythmia needing immediate defibrillation to
restore organized electrical activity.
7. What part of the ECG indicates ventricular depolarization?
• A) P wave
• B) QRS complex
• C) T wave
• Answer: B) QRS complex
• Explanation: The QRS complex represents the depolarization of the ventricles, leading to
ventricular contraction.
8. What pacing mode would be best for a patient with sinus node dysfunction and
AV block?
• A) AAI
• B) VVI
• C) DDD
• Answer: C) DDD
• Explanation: DDD pacing provides atrial and ventricular pacing with sensing, appropriate for
both sinus node dysfunction and AV block.
9. What effect does extending the PVARP have in dual-chamber pacemakers?
• A) Reduces ventricular pacing rate
• B) Reduces the risk of PMT
• C) Increases atrial contraction
• Answer: B) Reduces the risk of PMT
• Explanation: Extending the PVARP reduces the chance of pacemaker-mediated tachycardia by
preventing retrograde P wave sensing.
10. What ECG feature typically identifies atrial fibrillation?
• A) Regular P waves
1. What is the primary purpose of biventricular pacing in CRT?
• A) To increase atrial contraction
• B) To synchronize left and right ventricular contraction
• C) To improve AV node conduction
• Answer: B) To synchronize left and right ventricular contraction
• Explanation: Biventricular pacing improves the timing between left and right ventricular
contractions, which can enhance cardiac output in heart failure patients.
2. What interval adjustment is most likely to prevent pacemaker-mediated
tachycardia (PMT)?
• A) Shortening the AV delay
• B) Extending the PVARP
• C) Increasing pacing amplitude
• Answer: B) Extending the PVARP
• Explanation: Extending the post-ventricular atrial refractory period (PVARP) prevents the
pacemaker from detecting retrograde P waves, which can trigger PMT.
3. In a single-chamber ICD, what does VVI mode mean?
• A) Senses and paces the atrium only
• B) Senses and paces the ventricle, inhibited by intrinsic ventricular activity
• C) Dual-chamber sensing with ventricular pacing
• Answer: B) Senses and paces the ventricle, inhibited by intrinsic ventricular activity
• Explanation: VVI mode paces the ventricle when it doesn’t detect intrinsic ventricular activity,
avoiding unnecessary pacing.
4. What is the most appropriate device therapy for symptomatic bradycardia due
to AV block?
• A) ICD
• B) CRT device
• C) Pacemaker
• Answer: C) Pacemaker
• Explanation: A pacemaker is used for AV block to ensure regular ventricular contraction when
the AV node is not conducting effectively.
5. What cardiac condition is the main reason for CRT-D therapy?
• A) Atrial fibrillation
• B) Left bundle branch block with heart failure
, • C) Atrial flutter
• Answer: B) Left bundle branch block with heart failure
• Explanation: CRT-D is used in heart failure patients with left bundle branch block, which can
worsen ventricular dyssynchrony.
6. Which arrhythmia often requires defibrillation rather than synchronized
cardioversion?
• A) Atrial flutter
• B) Ventricular fibrillation
• C) Sinus bradycardia
• Answer: B) Ventricular fibrillation
• Explanation: Ventricular fibrillation is a chaotic arrhythmia needing immediate defibrillation to
restore organized electrical activity.
7. What part of the ECG indicates ventricular depolarization?
• A) P wave
• B) QRS complex
• C) T wave
• Answer: B) QRS complex
• Explanation: The QRS complex represents the depolarization of the ventricles, leading to
ventricular contraction.
8. What pacing mode would be best for a patient with sinus node dysfunction and
AV block?
• A) AAI
• B) VVI
• C) DDD
• Answer: C) DDD
• Explanation: DDD pacing provides atrial and ventricular pacing with sensing, appropriate for
both sinus node dysfunction and AV block.
9. What effect does extending the PVARP have in dual-chamber pacemakers?
• A) Reduces ventricular pacing rate
• B) Reduces the risk of PMT
• C) Increases atrial contraction
• Answer: B) Reduces the risk of PMT
• Explanation: Extending the PVARP reduces the chance of pacemaker-mediated tachycardia by
preventing retrograde P wave sensing.
10. What ECG feature typically identifies atrial fibrillation?
• A) Regular P waves
