Undetected coronary anomaly in tetralogy of Fallot: A preventable cause of persistent angina post redo surgery

A 44-year-old female with surgically corrected tetralogy of Fallot (TOF) presented with persistent angina and palpitations for 7 years following mechanical pulmonary valve replacement. Her immediate postoperative course was uncomplicated, and she was discharged home after a 7-day hospital stay. Electrocardiogram-gated coronary computed tomography angiography incidentally revealed an anomalous left anterior descending coronary artery (LAD) originating from the right coronary sinus without an intramural course, situated below the mechanical pulmonary valve. Positron emission tomography myocardial perfusion imaging demonstrated a large area of stress-induced ischemia in the LAD territory, along with a small area of transmural infarction in the distal LAD region. Subsequent cardiovascular magnetic resonance imaging (CMRI) confirmed extensive transmural late gadolinium enhancement in the LAD territory and right ventricular outflow tract. Adenosine stress perfusion CMRI showed no new inducible ischemia. This case underscores the importance of preoperative coronary imaging in patients with TOF undergoing reintervention to prevent inadvertent coronary injury and highlights the role of advanced imaging modalities in diagnosing and managing complex congenital heart disease.