[A case of isolated tricuspid regurgitation associated with persistent left superior vena cava].

We presented a rare case of isolated tricuspid regurgitation (TR) associated with persistent left superior vena cava (PLSVC). A 69-year old female was admitted to our hospital because of arrhythmia and cardiomegaly. Pansystolic cardiac murmur of Levine 2/6 was heard in her Erb's area. Remarkable cardiomegaly was revealed as 78% of cardiothoracic ratio and electrocardiographic findings showed atrial fibrillation. Echocardiographically, obvious dilatation of coronary sinus, right atrium and right ventricle were recognized and left atrium was also dilated moderately. Although results of right cardiac catheterization showed almost normal pressure, remarkable TR of grade IV was registered by Doppler echocardiography. Additional diagnosis of PLSVC drained to dilated coronary sinus was made by venography from the left antecubital vein. But evidence of other cardiac shunt diseases and other abnormalities which might be a cause of TR was negligible. It is reported, in general, that PLSVC drained to coronary sinus occurs asymptomatically, and there is no accepted theory that PLSVC is able to be a cause of TR alone. So, we diagnosed our case as rare isolated TR associated with PLSVC, and because only two such cases are reported in Japanese, we reported it.