Extrinsic compression of the left main coronary artery by atrial septal defect.

On rare occasions, extrinsic compression of the coronary artery can cause significant stenosis. We report a 42-year-old woman who was referred to our hospital for surgical repair of atrial septal defect. Cardiac 64-slice multi-detector computed tomography before the operation revealed the extrinsic compression of the proximal left main coronary artery by the marked dilatation of pulmonary trunk. The patient eventually underwent atrial septal defect closure and coronary artery bypass simultaneously. Four months after the operation, multi-detector computed tomographic scan revealed reduction of pulmonary trunk diameter and resolution of left main coronary artery narrowing.