Aortic valve commissural tear mimicking type A aortic dissection

A 52-year-old man came to the local emergency department with symptoms of heart failure and transient chest pain. Transthoracic echocardiography showed severe aortic regurgitation and a dilated ascending aorta. Aortic dissection was suspected, and he was transferred to our institution. Transesophageal echocardiography appeared to confirm the presence of a type A dissection. A mobile, linear structure was present in the proximal ascending aorta, suggesting the presence of dissection flap. Aortic cusp prolapse and severe aortic regurgitation were seen. At surgery, no aortic dissection was present. Rather, the commissure between right and left aortic valve cusps was separated from the wall of the aorta. Motion of the torn commissure with the cardiac cycle apparently led to the transesophageal echocardiographic appearance described. The ascending aorta was dilated. Histopathologic examination of the aorta confirmed the visual appearance of cystic medial necrosis. Aortic valve commissural tear is a rare event, which may lead to severe aortic regurgitation. This entity may lead to the false-positive transesophageal echocardiographic diagnosis of type A dissection.