Unroofed coronary sinus and persistent left superior vena cava.

This report describes a case of unroofed coronary sinus and persistent left superior vena cava discovered during an echocardiographic investigation for dilated pulmonary artery. An unroofed coronary sinus is a rare interatrial shunt that is commonly associated with a persistent left superior vena cava. The latter is a usual cause of a dilated coronary sinus. The detection of a dilated coronary sinus should therefore prompt the search for abnormal coronary sinus drainage and other cardiac abnormalities. The treatment of unroofed coronary sinus and persistent left superior vena cava is undertaken only after assessing the pre- and post-treatment haemodynamics of all co-existing abnormalities.