This patient had a pacemaker implanted for which conduction abnormality?

• A. Atrial Fibrillation With Rapid Ventricular Response
• B. High-Grade AV Block
• C. Sinus Tachycardia
• D. Ventricular Premature Complex

Answer: (B)

A pacemaker is used to treat slow heart rates caused by a disruption in the heart’s electrical conduction, especially in the AV (atrioventricular) pathway. When there is a high-grade AV block, the signal from the atria to the ventricles is severely impaired or totally blocked, so the ventricles beat too slowly or independently. The device steps in to pace the ventricles (and often the atria too) to maintain a safe heart rate and preserve coordination between atrial and ventricular contractions, which is why this conduction abnormality is the classic reason for pacing.

The other scenarios involve fast heart rhythms or ectopic beats rather than blocked conduction. Atrial fibrillation with rapid ventricular response causes an excessively fast rate, managed with rate or rhythm control rather than pacing. Sinus tachycardia is simply an elevated heart rate from various causes and does not require a pacemaker. Ventricular premature complexes are early beats from the ventricle, not a block in the conduction system needing pacing.