Epicardial Ablation of Ventricular Tachycardia - When and How?

Ventricular tachycardia (VT) appear as an inherent complication in the natural history of a structural heart disease due to scar progression and represents one of the leading causes of sudden cardiac death worldwide. Patients with structural heart disease and sustained VTs show an increased mortality rate and decreased life expectancy compared to those without documented VTs. Therefore, current guidelines for management of patients with ventricular tachycardia recommend urgent catheter ablation in patients with scar-related heart disease presenting with incessant VT or electrical storm and in those with ischemic heart disease and recurrent ICD shocks due to sustained VT (class I, level B). An early invasive therapeutic strategy is recommended for all VT-patients, especially for ischemic cardiomyopathy patients (class II, level B). Due to the complexity of myocardial scarring, mostly in the late stages of structural heart disease with extended epicardial involvement, the VT-ablation using only an endocardial approach is associated with a low level of success and event-free survival. More than that, there are certain structural heart diseases in which the myocardial scar initially develops predominantly at the epicardial surface (arrhythmogenic right ventricular cardiomyopathy and Chagas disease, up to 80% of non-ischemic dilated cardiomyopathy). Therefore today there is growing necessity for a combined endo-/ epicardial approach or even only epicardial instrumentation in VT-ablations. Emerging studies demonstrated a higher success rate in terms of noninducibility of VT and event-free survival when an epicardial ablation is added.