Giant Atrial Septal Artery Aneurysm with a Fistula to the Right Atrium.

An atrial septal artery aneurysm is a rare disease, especially accompanied with a fistula. During clinical practice, it is very important to clear the anatomical details of the coronary aneurysm before operation. In the current article, we report a giant atrial septal artery aneurysm originating from a branch of the RCA combined with a coronary right atrial fistula. The coronary artery aneurysm should be evaluated using multiple diagnostic and imaging modalities, such as echocardiography, coronary artery angiography, magnetic resonance imaging, and cardiac CT, especially three-dimensional reconstruction, which could help us to distinguish the physiological and anatomical characteristics of the CAA and fistula.