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.