Sustained Monomorphic Ventricular Tachycardia Decades After Ventricular Septal Defect Repair.

BACKGROUND

Ventricular tachycardia can occur decades after ventricular septal defect repair, but surface electrocardiogram (ECG) and noninvasive imaging cannot prove patch-dependent reentry.

CASE SUMMARY: A 57-year-old man with ventricular septal defect patch repair in infancy and no adult congenital heart disease follow-up presented with chest pain, dyspnea, and near-syncope. ECG showed sustained monomorphic ventricular tachycardia at 209 beats/min. Transthoracic echocardiography showed left ventricular ejection fraction 30%, right ventricular dysfunction, moderate-to-severe tricuspid regurgitation, and possible right ventricular thrombus. Transesophageal echocardiography demonstrated fixed postoperative-appearing tissue rather than thrombus. Coronary angiography showed no obstructive disease. After cardioversion, a secondary-prevention dual-chamber implantable cardioverter-defibrillator was placed, and sotalol was initiated with renal and ECG monitoring.

DISCUSSION: The case provides a framework for suspected but unproven postoperative scar-related ventricular tachycardia by separating substrate plausibility from circuit proof.

TAKE-HOME MESSAGE: Repaired ventricular septal defect carries lifelong arrhythmic risk; patch dependency requires electroanatomic mapping, whereas prevention decisions should follow clinical risk.