Prognostic Significance of Repetitive Ventricular Response During Radiofrequency Ablation of Premature Ventricular Complexes

Aims: Heat-induced repetitive ventricular response (automaticity) is frequently observed during radiofrequency ablation (RFA) of premature ventricular complexes(PVCs). We hypothesize that if the automaticity has similar morphology to the PVCs and if it is immediately followed by termination it indicates appropriate site and adequate lesion formation. We sought to investigate its prognostic significance in predicting long-term success.

Methods and results: Sixty-five consecutive patients (37 Female, mean age 42.1 ± 14.6 years) underwent RFA for PVCs from 66 sites. Fifty-nine patients had a structurally normal heart. In addition to PVCs, 6 patients had non-sustained ventricular tachycardia (VT) and another 6 had sustained VT. The most common site was right ventricular outflow tract (66.7%) followed by aortic cusps ( 9.1%),infra-valvular left ventricular outflow tract (9.0%), papillary muscles(3.0%) and others (12.1%). An irrigated catheter was used in 84.8% and automaticity was observed in 62.1%(41/66). Patients were divided into two groups - Group I: no repetitive response / repetitive response was seen but not during the successful lesion and PVCs disappeared gradually during later ablations (n=22). Group II: PVCs terminated immediately following repetitive response during the same RFA lesion (n=22). Acute success was seen in 80.3% and it was significantly more in group II (OR = 10.06; 95% CI = 1.23-82.04; p=0.003). After a median follow up of 12 months (range - 1 to 81 months) the success was persistent in 71.4%. The proportion of patients with long-term success was significantly higher in group II (OR=5.73; 95 % CI=1.15 - 28.58; p=0.022). However, the mere presence of repetitive response was not predictive of either acute or long-term success.

Conclusions: Both acute and long-term success rates were higher if the PVCs terminated immediately following repetitive ventricular response during the same RFA lesion.