AV block results in distal pacemaker sites generating the

AV block results in distal pacemaker sites generating the

• A. Atrial rhythm
• B. Junctional rhythm
• C. Ventricular rhythm
• D. Sinus rhythm

Answer: (C)

AV block stops impulses from the atria from reaching the ventricles, so the ventricles must be paced by a backup pacemaker located below the block. That distal focus is in the ventricular conducting system (His-Purkinje network), and when it takes over, the ventricles generate their own rhythm—the ventricular rhythm. This rhythm is typically slower and produces a wide QRS because activation starts in the ventricles rather than the normal rapid, coordinated atrioventricular conduction. So the distal pacemaker sites generate a ventricular rhythm.

AV block stops impulses from the atria from reaching the ventricles, so the ventricles must be paced by a backup pacemaker located below the block. That distal focus is in the ventricular conducting system (His-Purkinje network), and when it takes over, the ventricles generate their own rhythm—the ventricular rhythm. This rhythm is typically slower and produces a wide QRS because activation starts in the ventricles rather than the normal rapid, coordinated atrioventricular conduction. So the distal pacemaker sites generate a ventricular rhythm.