Endocardial Catheter Ablation for Refractory Ventricular Tachycardia Associated with Coronary Artery Disease

Abstract

Percutaneous endocardial electrode catheter ablation using stored direct current (DC) electrical energy was performed in five patients with recurrent ventricular tachycardia (VT) refractory to many antiarrhythmic drugs, including amiodarone. All had prior myocardial infarction and poor left ventricular function with ejection fractions ranging from 20% to 40%. Endocardial catheter and pace mappings were used to localize the earliest site of activation during VT. Under general anesthesia, two to six shocks with 200 to 300 joules DC energy per shock were delivered to the localized sites. Immediate complications included ventricular fibrillation in one patient, transient QRS complex widening in two patients, transient complete AV block with persistent first-degree AV block in one patient, and transient asystole in two patients. None had inducible VT immediately following ablation, or 4 to 6 days later; none had evidence of intracardiac clot by two-dimensional (2D) echocardiography on the third to fifth day. Peak creatine kinase ranged from 189 to 1610 IU/L with 9% to 18% MB fraction. During a follow-up of 6 to 30 months, three patients had no recurrence of VT. Two patients had recurrent VT with a slower rate, which was controlled with antiarrhythmic drugs. None had worsening of congestive heart failure. Two patients died of nonarrhythmic causes. We conclude that nonsurgical endocardial ablation of VT with an electrode catheter is effective for the treatment of refractory VT in selected patients with coronary artery disease.