Introduction
Premature ventricular contractions originating from the outflow tract
(OT), in particular left ventricular OT (LVOT), often conduct through a
preferential pathway to breakout into the global ventricular
myocardium.1,
2The presence of preferential
pathway conduction is mostly detected as fractionated presystolic
potentials preceding the QRS onset during PVCs and late potentials
during sinus rhythm (SR), and the site with those observations is
considered to be an optimal site for a successful
ablation.3-5 Based on
these findings, a radiofrequency (RF) application to the preferential
conduction is a well-developed strategy of PVC ablation, but the
electrophysiologic mechanisms and significance of presystolic and late
potentials during PVCs and SR at the successful ablation site have not
been fully clarified. We describe
a PVC case series in which the preferential pathway conduction was
3-dimensionaly visualized by coherent mapping with the conduction
velocity vector. This case series might add new insight into the
mechanisms of preferential pathways and PVCs.