Ablation of multifocal premature ventricular contractions using automated pace-mapping software.

Introduction And Objectives: Ablation of multifocal premature ventricular complexes (PVCs) is challenging. Activation mapping can be performed for the predominant morphology, but may be useless for other less prevalent ones. We aimed to describe the efficacy of an automated pace-mapping software-based ablation strategy for ablating the site of origin of multiple PVC locations.

Methods: Consecutive patients referred for ablation of multifocal PVCs were prospectively enrolled. Spontaneous PVC templates were recorded and a detailed pace-mapping map was generated to spot the site of origin of PVCs.

Results: A total of 47 PVCs were targeted in 21 patients (five and 16 patients with three or two PVCs morphologies each, respectively). Detailed pace-mapping comprising 73.5±41.6 different pacing locations was performed (best matching 97.2% [IQR 95.9-98.3%] similar to the clinical PVC). Activation points were acquired if possible, although ablation was only based on pace-mapping in 13 (27.6%) foci. Complete acute procedural success was obtained in 14 (66.7%) patients, while one PVC morphology was deliberately not ablated in five patients (23.8%). After 12.3±9.4 months of follow-up, PVC burden decreased from 24.4±10.4% to 5.6±5.0% (p<0.001). Interestingly, patients with acute procedural failures or with some PVCs deliberately not targeted during the procedure also experienced a significant decrease in PVC burden (30.0±8.9% to 11.9±3.5%, p=0.002).

Conclusion: Quantitative morphology-matching software can be used to obtain a detailed map identifying the site of origin of each single PVC, and successful ablation can be performed at these sites, even if activation points cannot be obtained due to the paucity of ectopic beats.