Radiofrequency Catheter Ablation of Polymorphic Premature Ventricular Contractions: Originating From the His Bundle Trunk?

BACKGROUND

Premature ventricular contractions (PVCs) truly arising from the His bundle trunk have not been documented. We report polymorphic narrow-QRS PVCs whose local Purkinje-ventricular interval (PV) interval matched the maximal His-ventricular interval (HV) in sinus rhythm yet were ablatable.

CASE SUMMARY: An 11-year-old boy (PVC burden: ∼25%) had normal imaging and laboratory results. Electrophysiology showed PV = HV during PVCs, implicating tissue adjacent to the proximal His. Reverse C-loop ablation at the high septal tricuspid annulus immediately eliminated PVCs with intact atrioventricular conduction.

DISCUSSION: Morphologically diverse PVCs shared a common focus near the proximal His. During PVCs, PV = HV supported a His-Purkinje substrate. Precise activation mapping with cautious, titrated energy enabled safe success.

TAKE-HOME MESSAGES: The earliest PVC potentials coincided with both left- and right-sided His recordings, mimicking a true His-trunk origin. The arrhythmia most likely arose from fasciculoventricular fibers-direct His-septal connections-providing a discrete, safely ablatable target.