Published online Aug 16, 2016. doi: 10.12998/wjcc.v4.i8.219
Peer-review started: February 23, 2016
First decision: March 25, 2016
Revised: March 31, 2016
Accepted: May 31, 2016
Article in press: June 2, 2016
Published online: August 16, 2016
A 15-year-old boy with transposition of the great arteries (TGA) and neonatal arterial switch operation (ASO) presented with complete occlusion of the left main coronary artery (LMCA). Intra-operatively, an intramural left coronary artery was identified. Therefore, since age 7 years he had a series of screening exercise stress tests. At 13 years old, he had 3 to 4 mm ST segment depression in the infero-lateral leads without symptoms. This progressed to 4.2 mm inferior ST segment depression at 15 years old with normal stress echocardiogram. Sestamibi myocardial perfusion scan and cardiac magnetic resonance imaging was inconclusive. Therefore, a coronary angiogram was obtained which showed complete occlusion of the LMCA with ample collateralization from the right coronary artery system. This was later confirmed on a computed tomogram (CT) angiogram, obtained in preparation of coronary artery bypass grafting. The case illustrates the difficulty of detecting coronary artery stenosis and occlusion in young patients with rich collateralization. Coronary CT angiogram and conventional angiography were the best imaging modalities to detect coronary anomalies in this adolescent with surgically corrected TGA. Screening CT angiography may be warranted for TGA patients, particularly for those with known coronary anomalies.
Core tip: In complete transposition of the great arteries (TGA), neonatal arterial switch operation offers excellent long term survival. Yet there can be late coronary artery complications. In this case, an asymptomatic teenager had an abnormal screening exercise-stress test leading to the identification of complete left coronary occlusion. This case illustrates how rich coronary collateralization can obscure even complete coronary occlusion. As such, young patients pose a unique diagnostic challenge. Coronary computed tomogram (CT) angiogram and conventional angiography were the best imaging modalities to detect the problem. Screening CT angiography may be warranted for TGA patients, particularly for those with known coronary anomalies.