Catheter ablation of premature ventricular complexes arising from the left fascicular system

Background: Idiopathic premature ventricular complexes (PVCs) that originate from the left fascicular system have rarely been reported.

Objective: The present study aimed to investigate the electrophysiological characteristics and the ablation strategy for this category of PVCs.

Methods: Of 648 patients with idiopathic PVCs, 27 were enrolled in this study. All the PVCs presented with a relatively narrow QRS complex and right bundle branch block morphology. The mean QRS duration was 117.4 ± 8.6 ms. Radiofrequency catheter ablation was applied at the site recording the earliest fascicular potential (FP).

Results: The origin of PVCs was as follows: 15 originating from the left anterior fascicle, 7 originating from the left posterior fascicle, 2 originating from the left middle fascicle, and 3 originating from the common trunk of the left bundle branch. The earliest local FP preceded the onset of the QRS complex by 32.7 ± 6.4 ms. The immediate ablation success rate was 100%. Three patients had recurrent PVCs during follow-up. The total success rate of a single procedure was 88.9%.

Conclusion: Ablation of PVCs originating from the left fascicular system guided by an earliest presystolic FP was found to be safe and effective.