Radiofrequency Catheter Ablation of Polymorphic Premature Ventricular Contractions: Originating From the His Bundle
Lu Zhao1, Yi-Xiang Lin1, Xue-Cun Liang1
1Pediatric Heart Center, Children's Hospital of Fudan University, National Children's Medical Center, Shanghai, China.
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.
Related Concept Videos
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Dysrhythmias IV: Characteristics of Bradyarrhythmias
Dysrhythmias III: Characteristics of Dysrhythmias
Dysrhythmias VI: Management of Dysrhythmias
Dysrhythmias II: Classification of Tachyarrhythmias


