Patient with transposition of great arteries post arterial switch operation and retro-pulmonary left coronary artery, presented with chest pain on exertion. Normal systolic function at rest. However, on stress perfusion, the images reveal perfusion defects in the left anterior descending artery and circumflex territories. View Video 5 at http://movie-usa.glencoesoftware.com/video/10.1530/ERP-19-0048/video-5.