American Board of Internal Medicine (ABIM) Certification Practice Exam

What is one of the indications for pacemaker placement?

1. Asymptomatic bradycardia without any pauses

2. Symptomatic bradycardia with a reversible cause

3. Atrial fibrillation with 5-second pauses

4. Heart rate persistently above 40/min

The correct answer is: Atrial fibrillation with 5-second pauses

Atrial fibrillation with 5-second pauses is a significant indication for pacemaker placement due to the risk of prolonged periods of bradycardia that can lead to syncope or other hemodynamic instability. In patients with atrial fibrillation, the heart rate can vary significantly, and if the heart pauses for 5 seconds or longer, it may indicate that the conduction system is not adequately responding to the needs of the body. Such extended pauses can result in symptoms like dizziness, confusion, or even fainting, thereby necessitating a pacemaker to provide adequate heart rate support. Conversely, asymptomatic bradycardia without pauses does not generally require intervention as the patient is not experiencing significant symptoms that would warrant a pacemaker. Symptomatic bradycardia with a reversible cause typically resolves with the treatment of the underlying condition, eliminating the need for permanent pacing in those cases. When the heart rate is persistently above 40/min, this usually falls within a range considered too high for pacemaker placement, which is indicated primarily for bradycardic rates that pose a risk to the patient.