Nonendocardial Isthmus Involving a Protected Part Within the Endocardial Scar in an Ischemic Ventricular Tachycardia

A 73-year-old man with ischemic cardiomyopathy underwent ventricular tachycardia (VT) ablation. During right ventricular pacing, substrate mapping was performed using EnSite Precision (Abbott, St. Paul, Minnesota) with an Advisor HD Grid Mapping Catheter (Abbott). The bipolar and unipolar voltage