Infrequent intraprocedural premature ventricular complexes: implications for ablation outcome.

Background: Frequent premature ventricular complexes (PVCs) can be eliminated with an ablation procedure. Ablation success rates have been reported to be in the 80% range. Reasons for failure of ablation have not been described in detail. The purpose of this study was to determine whether the paucity of PVCs at the beginning of the ablation procedure affects the outcome.

Methods: Catheter ablation was attempted in a consecutive series of 194 patients (age: 50 ± 14 years, 91 male, ejection fraction: 56.4 ± 8.4%) with frequent idiopathic PVCs. Based on receiver operator characteristics (ROC) analysis, patients were divided into 2 groups: Patients with frequent PVCs (≥32 PVCs within the first 30 minutes of the procedure: n = 135 [70%]); and patients with infrequent PVCs (<32 PVCs within the first 30 minutes of the procedure: n = 59 [30%]). Procedural outcomes were compared at 3 months postablation. A successful ablation was defined as a ≥80% reduction in the PVC burden compared to baseline.

Results: A successful procedure was performed in 148 patients (76%) resulting in a decrease in the PVC burden from 19.1 ± 13.6% to 0.38 ± 0.98%(P < 0.0001). Patients with frequent intraprocedural PVCs had a higher success rate than patients with infrequent intraprocedural PVCs (85% vs. 56%, P = 0.0001). Administration of sedation was no different in the 2 groups. The paucity of PVCs was independent of the site of origin in predicting procedural failure (OR: 6.9, 95% CI: 3.0-16.2 P = 0.0001).

Conclusion: Paucity of PVCs at the beginning of an ablation procedure is associated with a lower ablation success rate independent of the site of origin.