日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

Unroofed coronary sinus syndrome (URCS) is characterized by a defect in the common wall between the coronary sinus and left atrium, resulting in left-to-right shunting, which is similar to that observed in atrial septal defects. In left-sided obstructive heart disease, this left-to-right shunting is essential for maintaining circulation, and URCS can play a critical role in sustaining life. We describe a case of mitral valve atresia with a single ventricle that was not diagnosed at birth but was later identified as URCS at 2 months of age, showing a tendency for spontaneous closure. In the present case, URCS was essential for circulatory maintenance, necessitating surgical atrial septal defect enlargement. It is crucial to carefully monitor patients with congenital heart disease when URCS is suspected, considering its potential contribution to hemodynamics and the possibility of spontaneous closure, which can be fatal. We also discuss the clinical course of this case, the URCS pathophysiology, and the mechanisms underlying its spontaneous closure.