Prenatal diagnosis of cor triatriatum sinister associated with early pericardial effusion: A case report

BACKGROUND: Cor triatriatum sinistrum or cor triatriatum sinister is a rare congenital heart disease that accounts for approximately 0.1% of all cardiac abnormalities. It is defined as the presence of an anomalous septum that divides the left atrium into two cavities, and in most cases, it can be asymptomatic or less frequently very severe. CASE SUMMARY: A 37-year-old pregnant woman visited our hospital. In the first trimester scan, we detected signs of fluid in the pericardium (pericardial effusion) that reached the atriums. In the third trimester, an anomalous septum in the left atrium suspicious of cor triatriatum sinister was detected. Expectant management was decided, the pregnancy evolved normally and resulted in uncomplicated delivery of a healthy child. The findings in the prenatal scan were confirmed by echocardiography and the diagnosis of cor triatriatum sinister was confirmed. The newborn was asymptomatic at all times. CONCLUSION: We show expectant management of cor triatriatum sinister and suggest an association between this entity and early pericardial effusion.