Radiofrequency catheter ablation of frequent monomorphic ventricular ectopic activity

Frequent ventricular ectopic beats can result in severe symptoms and may even be incapacitating in some patients. Although radiofrequency catheter ablation is an effective and safe therapy for drug refractory idiopathic ventricular tachycardia, it has not been widely used in ventricular ectopy. The purpose of this study was: (1) to assess the potential role of catheter ablation in eliminating monomorphic ventricular ectopy in symptomatic patients regarding feasibility and safety and (2) to determine the usefulness of various mapping strategies.

Forty-one patients with symptomatic ventricular ectopic activity (right ventricular origin in 23 patients, left ventricular origin in 18 patients) were enrolled. The mean frequency of ventricular ectopic beats was 1512+/-583/hour documented by Holter ECG monitoring. These patients had previously been unable to tolerate or had been unsuccessfully treated with a mean of 3+/-1 antiarrhythmic agents. The site of origin was mapped using earliest endocardial activation times, unipolar electrograms and pace mapping. Radiofrequency ablation was successful in 34 (83 %) of 41 patients. Multivariate logistic regression analysis revealed pace mapping as the only independent predictor for a successful ablation site (P < 0.01). After a follow-up of 3 months, the overall success rate was 71%. The mean frequency of ventricular ectopic beats after successful ablation was 12+/-10 ventricular premature beat/hour.

Radiofrequency catheter ablation is an effective and safe treatment for frequent symptomatic drug refractory monomorphic ventricular ectopic activity. Pace mapping predicts best successful ablation of ventricular ectopic beats.