Epicardial Ventricular Tachycardia Ablation: A Contemporary Review of Indications, Techniques, and Practical Approaches for Challenging Substrates.

Epicardial ablation is an increasingly important treatment for refractory ventricular tachycardia (VT), particularly in nonischemic cardiomyopathy or when the substrate is epicardial or mid-myocardial. This review provides an overview of the pathophysiology and disease-specific characteristics of VT substrates, with a particular focus on epicardial involvement and indications based on electrocardiographic, imaging, and clinical findings. We present advanced substrate-mapping strategies, including functional and high-resolution approaches, and practical examples of three-dimensional mapping using the CARTO™ (Biosense Webster, Diamond Bar, CA, USA) and EnSite™ (Abbott, Abbott Park, IL, USA) systems to overcome the known limitations of conventional mapping techniques. In the latter part of the review, we discuss the technical aspects of epicardial access, as well as the clinical challenges and strategies for challenging scenarios, such as bipolar ablation and ablation after prior cardiac surgery, supported by practical examples from our institution. We also highlight future perspectives. These insights are expected to contribute to the optimization of treatment strategies for refractory epicardial VT and to support the development of more precise and durable patient care.