We report on a case of coronary sinus rupture that happened during pla
cement of a cardioplegia balloon catheter and its subsequent repair. F
irst, the defect was oversewn, however, not successfully. Under cardio
pulmonary bypass and cardioplegic arrest, a pericardial patch was used
to reconstruct the coronary sinus. Six months after the operation, bl
ood drained during diastole into the right atrium but the flow was par
tially reversed during systole.