Successful Catheter Ablation of Ventricular Tachycardia Precipitated by Cardiac Resynchronization Therapy.

A patient with ischemic cardiomyopathy and an implantable cardioverter-defibrillator underwent an upgrade with an epicardial left ventricular lead, which precipitated recurrent ventricular tachycardia (VT). An electrophysiological study with electroanatomic mapping showed the site of the left ventricular lead to be part of the re-entrant circuit, and substrate modification of an endocardial channel led to the resolution of VT and an improvement in symptoms.