Two cases of incidentally diagnosed idiopathic left atrial appendage ostial stenosis.

We report here on 2 cases of idiopathic left atrial appendage ostial stenosis (LAA), and this rare finding was detected on transesophageal echocardiography. Its clinical implication is still unknown, given the small number of reported cases. Incompletely ligated LAA has characteristics similar to those observed in idiopathic LAA ostial stenosis, including the narrowed orifice, the small LAA cavity and the accelerated blood flow across the stenotic area. Since the incompletely ligated LAA has been reported to be complicated with thromboembolic events, we can assumed that the patients with idiopathic LAA ostial stenosis have a higher risk of thromboembolism than those with a normal LAA structure.