Background: Cor triatriatum sinister is rare congenital heart disease. It is mainly presented in childhood and often accompanied with other congenital anomalies. The cases with cor triatriatum treated surgically in adults and accompanied with severe mitral regurgitation are very rare.
Case report: We present a case with diagnosed cor triatriatum and severe mitral regurgitation. The diagnose was made by echocardiography. She was a female 25 years that was hospitalised with signs of heart failure NYHA II-III.
Conclusion: We performed the resection of the membrane in the left atrium and repair of a mitral valve according to Alfieri. The patient did very well after the surgery.
Keywords: Congenital heart disease; Cor triatriatum; Mitral regurgitation.