A case of mitral-aortic intervalvular fibrosa aneurysm with unique flow patterns and long-term natural survival.

We report a patient with a large aneurysm of mitral-aortic intervalvular fibrosa as a complication of prosthetic aortic valve endocarditis diagnosed on transthoracic echocardiography. This aneurysm began to expand with atrial systole, filled fully during ventricular systole, and collapsed in diastole on transesophageal examination. The patient refused corrective surgery and has survived on medical treatment for close to 2 years.