ABLATION OF VENTRICULAR-TACHYCARDIA DUE TO A POSTINFARCT VENTRICULAR SEPTAL-DEFECT - IDENTIFICATION AND TRANSECTION OF A BROAD REENTRY LOOP

Outer Loop Tachycardia. Introduction: Ventricular tachycardia (VT) aft er postinfarct ventricular septal defect (VSD) repair has not been wel l characterized.Methods and Results: A 55-year-old man developed refra ctory VT after inferior wall infarction and VSD repair. Entrainment de monstrated a broad reentry circuit path (outer loop) between the tricu spid annulus and VSD patch. A series of radiofrequency (RF) lesions tr ansected this path, abolishing VT and producing conduction block betwe en the inferior and superior aspects of the basal right ventricular se ptum. Conclusion: Some VTs have broad reentry loops requiring ablation by a series of RF lesions across the path to create a line of block. This approach is analogous to that for atrial flutter.