ABSTRACT
Ventricular tachycardia ablation is the primary treatment modality for medication refractory ventricular arrhythmias. In patients with structural heart disease, these arrhythmias are often re-entrant in nature and can involve complex three-dimensional scars with variable involvement of the endocardium, mid-myocardium, and/or epicardium. Epicardial access may also be required in a small percentage of patients with no structural heart disease with premature ventricular complexes or ventricular tachycardia that cannot be successfully ablated from an endocardial approach. In rare instances, ablation of supraventricular tachycardia may require epicardial access as well. Right ventricular perforation is the most common risk given that epicardial access is typically obtained with a “dry” pericardium or with only trace pericardial fluid. Ventricular tachycardia ablation, particularly in patients with structural heart disease, involves complex substrates that are three-dimensional and may frequently involve the epicardial surface of the heart.
