With the widespread use of implantable cardioverter-defibrillators, an increasing number of patients present with ventricular tachycardia
(VT). Large multicentre studies have shown that ablation of VT successfully reduces recurrent VT and this procedure is being performed
by an increasing number of centres. However, for a number of reasons, many patients experience VT recurrence after ablation. One
important reason for VT recurrence is the presence of an epicardial substrate involved in the VT circuit which is not affected by
endocardial ablation. Epicardial access and ablation is now frequently performed either after failed endocardial VT ablation or as first-line
treatment in selected patients. This review will focus on the available evidence for identifying VT of epicardial origin, and discuss in which
patients an epicardial approach would be benefitial.