RADIOFREQUENCY CATHETER ABLATION OF VENTRICULAR-TACHYCARDIA AFTER MYOCARDIAL-INFARCTION

Background-Patients with ventricular tachycardia (VT) after myocardial infarction often have multiple morphologies of inducible VT, which co mplicates mapping and is viewed by some as a relative contraindication to ablation, Attempting to identify and target a single ''clinical'' VT is often limited by inability to obtain 12-lead ECGs of VTs that ar e terminated emergently or by defibrillators. This study assesses the feasibility of ablation in patients selected without regard to the pre sence of multiple VTs by targeting all VTs that allow mapping, Methods and Results-Radiofrequency catheter ablation targeting all inducible monomorphic VTs that allowed mapping was performed in 52 patients with prior myocardial infarction. Antiarrhythmic drug therapy had failed i n 41 (79%) patients including amiodarone in 36 (69%) patients. An aver age of 3.6+/-2 morphologies of VT were induced per patient. More than 1 ablation session was required in 16 (31%) patients. Complications oc curred in 5 (10%) patients, including 1 (2%) death caused by acute myo cardial infarction, During follow-up 59% of patients continued to rece ive amiodarone; 23 (45%) had implantable defibrillators. During a mean follow-up of 18+/-15 months (range 0 to 51 months) 1 patient died sud denly, 2.died from uncontrollable VT, and 5 died from heart failure. T hree-year survival rate was 70+/-10%, and race for risk of VT recurren ce was 33+/-7%. Conclusions-Radiofrequency catheter ablation controls VT that is sufficiently stable to allow mapping in 67% of patients des pite failure of antiarrhythmic drug therapy and multiple inducible VTs . However, ablation was largely adjunctive to amiodarone and defibrill ators in this referral population.