Epicardial Ventricular Tachycardia Ablation: Clinical Practice and Recent Developments

It is ambiguous whether one should use this approach only after an endocardial VT ablation failure or when the ECG of clinical VT suggests an epicardial origin. Consequently, multiple published ECG criteria may be used to predict epicardial VT origin. A maximal deflection index (MDI, the longest precordial lead onset-peak time divided by total QRS duration) of 0.55 or more is reported to identify idiopathic epicardial VT with high sensitivity and specificity (4).