RADIOFREQUENCY CATHETER ABLATION OF VENTRICULAR-TACHYCARDIA FOLLOWINGIMPLANTATION OF AN AUTOMATIC CARDIOVERTER-DEFIBRILLATOR

Objectives: The present study reports on the complementary role of two nonpharmacological options of antiarrhythmic therapy. Background: Cat heter ablation, antitachycardia surgery, and the implantable cardiover ter defibrillator (ICD) have become important tools in the management of ventricular tachyarrhythmias. However, the emergence of ventricular tachyarrhythmias after implantation of an ICD is possible because the arrhythmogenic substrate is not affected. Patients and Methods: Six o f 180 patients developed frequent episodes of monomorphic ventricular tachycardia (n = 2) or incessant ventricular tachycardia (n = 4) follo wing implantation of an ICD and underwent radiofrequency (RF) catheter ablation. Catheter ablation was performed using a RF generator HAT 20 0. Energy was delivered between a 4-mm tip electrode of the ablation c atheter and a patch electrode. Results: Catheter ablation was done 6.8 +/- 5 months following ICD implantation; 6 +/- 2.2 RF impulses were d elivered at the site of origin of ventricular tachycardia chararcteriz ed by early endocardial activation during ventricular tachycardia, ide ntical pace mapping and long latency between stimulus, and QRS-complex in five patients. New bundle branch reentry was the underlying mechan ism of ventricular tachycardia in one patient. RF catheter ablation re sulted in termination of incessant ventricular tachycardia. Immediatel y postablation, the documented ventricular tachycardia was rendered no ninducible in all patients. No ICD malfunctions have been observed. On e patient died due to heart failure 24 hours after successful ablation of the incessant ventricular tachycardia. During a follow-up of 5-19 months, episodes of ventricular tachycardia recurred in four patients. All episodes could be controlled by the ICD without frequent cardiove rsions. Conclusion: RF catheter ablation is a complementary therapeuti c option in case of frequent or incessant ventricular tachycardia afte r ICD implantation.