In ventricular tachycardia, what best describes a capture beat?

• A. A beat originating from the VT focus
• B. A premature ventricular beat not part of VT
• C. A heart beat with atrial origin
• D. A normal-looking beat conducted via the His-Purkinje system during VT

Answer: (D)

Capture beats happen when a supraventricular impulse is conducted through the normal His-Purkinje system during ventricular tachycardia, so a beat appears with a normal, narrow QRS morphology despite the rest of the rhythm being VT. This shows that the ventricles can still be activated by the usual conduction pathway for that beat, effectively “capturing” the ventricles even though the overall rhythm is VT. It’s different from a VT-origin beat, which would keep the wide VT morphology, and from a premature ventricular beat, which is ectopic ventricular activation not conducted through the normal pathway. It’s also distinct from a fusion beat, which blends VT and normal conduction to produce an intermediate morphology; a capture beat is a pure, normal-looking beat within VT because the impulse fully traverses the His-Purkinje system.