Ablation of Ventricular Tachycardia Due to a Postinfarct Ventricular Septal Defect:

Identification and Transection of a Broad Reentry Loop


William G. Stevenson, M.D., Cardiovascular Division. Brigham and Women's Hospital, 75 Francis St., Boston. MA 02115. Fax: 617-732-71.M; E-mail: WGSTEVENSO(r)BICS.BWH.HARVARD.EDU


Outer Loop Tachycardia. Introduction: Ventricular tachycardia (VT) alter postinfarct ventricular septal defect (VSD) repair has not been well characterized.

Methods and Results: A 55-year-old man developed refractory VT after inferior wall infarction and VSD repair. Entrainment demonstrated a broad reentry circuit path (outer loop) between the tricuspid annulus and VSD patch. A series of radiofrequency (RF) lesions transected this path, abolishing VI’ and producing conduction block between the inferior and superior aspects of the basal right ventricular septum.

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.