[Radiofrequency catheter ablation of ventricular tachycardia in patients with an implantable defibrillator. Long-term follow-up].

INTRODUCTION AND OBJECTIVES The frequent occurrence of ventricular tachycardia can be a serious problem for patients with an implantable defibrillator, and may necessitate adjuvant antiarrhythmic therapy or radiofrequency catheter ablation. We analyzed the long-term results obtained with this latter therapy in patients suffering from frequent or continuous ventricular tachycardia. PATIENTS AND METHOD Eighteen ablation procedures were performed in 11 patients who had a defibrillator implanted because of previous syncopal ventricular tachycardia. All were men, aged 67.64 (5.87) years; 10 patients had had a myocardial infarction 15.50 (5.08) years earlier, and one suffered from arrhythmogenic right ventricular dysplasia. RESULTS Electrophysiologically, treatment was initially successful in 8 patients (72.73%). After a follow-up period of 39.10 (24.70) months, the number of defibrillator discharges decreased significantly in all patients, from 52.82 (35.73) to 0.64 (1.03) (P=.001). During follow-up, ventricular tachycardia occurred in nine patients. In five, it took the same form as the ablated ventricular tachycardia. Six patients needed additional ablation procedures: two because of initial failure, three because of recurrence, and one because a different ventricular tachycardia occurred. In addition to the good electrophysiological results obtained, long-term clinical evolution was favorable in all patients. CONCLUSIONS Radiofrequency ablation successfully disrupts frequent or continuous ventricular tachycardias and significantly reduces the defibrillator discharge rate even when ablation has failed electrophysiologically. It is particularly useful in these latter critical situations, in which other therapies are not sufficiently effective. Because our patients mainly had ischemic heart disease and were highly susceptible to new arrhythmias during follow-up, ablation complemented rather than replaced the implantable defibrillator.