Cardiac Magnetic Resonance Imaging in a Patient With Nonatherosclerotic Acute Myocardial Infarction

A patient in their 40s with a history of bilateral Blalock-Taussig shunts and pulmonary artery banding in childhood for congenital heart disease developed angina with elevated troponin levels. Computed tomography coronary angiography demonstrated proximal occlusion of a large coronary artery branch with multiple calcified masses within the epicardium, likely fibromas or myofibromas, with the largest retrosternal mass causing extrinsic compression and luminal obliteration of the anterior coronary artery. Cardiac magnetic resonance imaging showed akinesia as seen in this video and transmural late gadolinium enhancement in the left ventricular apex and septum consistent with a completed infarct. External compression of epicardial coronary arteries resulting in progressive luminal narrowing and myocardial ischemia is an uncommon cause of nonatherosclerotic acute myocardial infarction. Click the Related Article link for a complete discussion.