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How Calcium Channel Blockers Slow the Ventricular Response in Atrial Fibrillation Jun 06, 2025

Atrial fibrillation (AF) is marked by chaotic atrial activity that can drive the ventricles at dangerously high rates. While the atria may be firing at 400–600 impulses per minute, the AV node acts as a gatekeeper—filtering which signals reach the ventricles. Calcium channel blockers (CCBs), particu...

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Why Atrial Fibrillation with Ventricular Pacing Can Appear Regular Jun 02, 2025

Atrial fibrillation (AF) is classically described as an irregularly irregular rhythm, defined by chaotic atrial activity and a ventricular response that lacks any predictable pattern. However, a unique exception occurs in patients who have ventricular pacing, especially those with complete AV block ...

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Atrial Fibrillation with Complete Heart Block: The Physiology of “Regularized” Atrial Fibrillation Jan 24, 2025

Atrial fibrillation (AF) is classically characterized by an irregularly irregular ventricular rhythm due to chaotic atrial depolarization and random conduction through the atrioventricular (AV) node. However, in rare instances, AF can produce a regular ventricular rhythm—a phenomenon that occurs whe...

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