Case images: Left atrial appendage ostial stenosis in a patient with rheumatic mitral valve disease.

A 45-year-old female was admitted to the outpatient clinic with complaint of dyspnea on exertion. Cardiac examination revealed a diastolic murmur best heard at apex, but was otherwise unremarkable. Transthoracic echocardiography and transesophageal echocardiography (TEE) revealed moderate mitral and aortic regurgitation with severe rheumatic mitral stenosis (Video 1*). TEE revealed left atrial appendage (LAA) orifice stenosis with peak velocity of 1.6 m/s (Figure A). Color Doppler examination of the LAA orifice showed a turbulent flow (Figure B, Video 2*). Spontaneous echo contrast and thrombus were not observed within the LAA. The patient was ultimately referred to cardiac surgery for valve replacement and LAA ligation. LAA ostial stenosis incidentally detected on TEE is a very rare clinical entity. LAA ostial stenosis can be classified into isolated LAA ostial stenosis and remnant narrowness after incomplete LAA ligation. Although pathophysiology and clinical implications of LAA ostial stenosis are still unknown, it has been suggested that isolated LAA ostial stenosis may be a kind of congenital anomaly and possible variant of cor triatriatum, possibly predisposing the patient to thrombus formation in the LAA. The present patient had no history of surgical or catheter-based intervention. LAA ostial stenosis was noticed on color Doppler examination. Based on the present findings, it was determined that the patient had isolated LAA ostial stenosis, unrelated to rheumatic mitral valve stenosis. Greater experience and long-term follow-ups are needed to expose the exact pathophysiology and clinical significance of LAA ostial stenosis. 533