Coronary Fistula-Induced Ventricular Tachycardia From Thrombotic Cyst Compression: A Case Report.

BACKGROUND: Coronary artery fistula (CAF) complicated by thrombotic cyst formation is a rare cause of ventricular tachycardia (VT), involving ischemia and mechanical compression. CASE PRESENTATION: A 55-year-old woman presented with palpitations, chest pain, monomorphic VT (negative V1-V6), and elevated troponin I. Imaging revealed a large right ventricular cyst. Surgical resection confirmed a thrombotic cyst communicating with a CAF. Postoperative VT recurred, leading to cardiogenic shock and death. CONCLUSIONS: CAF-related thrombotic cysts can cause irreversible myocardial fibrosis, creating a persistent VT substrate unresponsive to anatomical intervention alone. ECG markers (fragmented QRS, ST depression) reflect irreversible damage.