Endocardial and Epicardial Ablation of Ventricular Tachycardia Associated with Organic Heart Disease

Abstract

Previous studies have demonstrated the effectiveness of targeting areas for radiofrequency catheter ablation (RFCA) in cases of unmappable ventricular tachycardia (VT) on the basis of voltage mapping using the electroanatomical mapping system. An abnormal area in right and left ventricle mapping was generally defined as 0.1–<0.6 mV, and dense scars as <0.1 mV. The basic linear ablation design criteria were: Lesions must cross through the LVA, where a good pace mapping could be obtained; Lesions must combine between scar and scar within the LVA; and Lesions must extend from the scar to the normal voltage area. RF was not applied to nonarrhythmogenic areas. At 38±18 months follow-up, 93% of the patients were free of VT after one or more endocardial ablations in 29 patients with old myocardial infarction. Failure to ablate VT from the endocardium may require an epicardial mapping in non-ischemic heart disease. The VT substrate of dilated cardiomyopathy is distributed at more epicardial sites than endocardial sites, and a combined endocardial and epicardial ablation may be effective in such cases.