Cor Triatriatum

Cor triatriatum is a rare congenital anomaly characterized by an embriologic defect in which the common pulmonary vein fails to connect to the left posterior atrial wall. As a result, the left atrium is divided by a fibromuscular membrane in 2 chambers, the posterosuperior chamber that receives the drainage of the pulmonary veins, and the anteroinferior chamber that continues with the mitral valve. We report on a 45-year-old woman whose diagnosis was made because of exertional dyspnea and paroxistic atrial fibrillation. Echocardiography showed a characteristic linear echodense structure crossing the left atrium (Figure 1A). Magnetic resonance and right catheterization confirmed the diagnosis of cor triatriatum (Figure 1B,C,D). The patient underwent surgical correction.

Figure 1. Echocardiography (A) and magnetic resonance and right catheterization (B-D) confirming cor triatriatum diagnosis