Right coronary ostium occlusion by aortic valve tumor during systole.

Here, we present a case of acute myocardial infarction caused by an aortic valve tumor. Electrocardiography (ECG)-gated four-dimensional computed tomography revealed obstruction of the right coronary ostium by a mobile mass during systole. To ensure an accurate diagnosis of angina in patients without significant coronary artery disease, ECG-gated four-dimensional computed tomography is useful because it can simultaneously visualize the coronary ostium and arteries, aortic valve leaflets, and mass.