TREATMENT OF VENTRICULAR-TACHYCARDIA BY TRANSCATHETER RADIOFREQUENCY ABLATION IN PATIENTS WITH ISCHEMIC-HEART-DISEASE

Background Recurrent sustained ventricular tachycardia (VT) is not res ponsive to antiarrhythmic drugs in the majority of patients, who there fore need therapy with nonpharmacological methods. We evaluated prospe ctively the feasibility, safety, and efficacy of transcatheter radiofr equency (RF) ablation of VT in 21 selected patients with ischemic hear t disease and VT. Methods and Results Twenty-one patients with ischemi c heart disease and recurrent, drug-refractory VT documented by 12-lea d ECG were selected who had sufficient hemodynamic tolerance of VT to undergo transcatheter mapping. Documented clinical VT was reproduced b y programmed cardiac stimulation (PCS), and the site of origin was loc alized by a combination of techniques, including pace mapping, activat ion-sequence mapping, recordings of middiastolic potentials, and appli cation of resetting and entrainment principles. RF current at 55 V was applied (3.8+/-3.1 applications per patient) for as long as 30 second s at a time to target sites. Twenty-four distinct clinical VTs (mean c ycle length, 445+/-52 milliseconds) were mapped and ablated in 21 pati ents. In 17 of 21 patients (81%), the procedure was acutely successful , and the target clinical VT could no longer be induced by PCS after t he procedure, whereas in 4 patients, clinical VT remained inducible. B y contrast, VTs with shorter cycle length and different QRS morphology than the ablated VT could still be induced by PCS in 12 of 21 patient s. One patient died in intractable congestive heart failure 10 days af ter the procedure, and the remaining 20 are alive at the end of the fo llow-up period. The majority of the patients continued to be treated w ith at least one additional mode of antiarrhythmic therapy; 12 patient s were still taking antiarrhythmic drugs, and 9 patients received an i mplantable cardioverter/defibrillator. During a mean follow-up period of 13.2+/-5.0 months, 9 of 20 patients (45%) had recurrent VT. In 4 pa tients, the recurrent VT was different than the previously ablated one . Clinical VT recurred in all 4 patients in whom RF ablation had been acutely unsuccessful. Four patients with recurrent VT underwent repeat RF ablation procedures that were acutely successful and had no furthe r recurrence. Conclusions Transcatheter RF ablation is feasible but ha s only moderately high efficacy in a small, selected group of patients with ischemic heart disease and drug-refractory, highly frequent, hem odynamically tolerated, sustained VT, In the majority of the patients, this treatment technique is palliative rather than definitive, and ma ny of the patients continue to require other methods of antiarrhythmic therapy.