Termination of Ventricular Tachycardia by Prepotential Exit Block.

Abstract

Discrete prepotentials (PPs) mapped within the aortic sinuses of Valsalva are considered reliable targets for the ablation of idiopathic premature ventricular complexes (PVCs) and ventricular tachycardias. A critical conduction time is required for the PVC to manifest, as evidenced by a distinct isoelectric segment between the discrete PPs and the ventricular electrograms, consistent with the limitations imposed by the local refractoriness of the tissue at the exit site.