Giant right atrium: case report of a rare congenital disease in adulthood

Excerpt

A 29 year old man presented with palpitation, fatigue and dyspnea on exertion. Physical examination and electrocardiogram revealed a soft holosystolic murmur in precordium, elevated jugular venous pressure and atrial fibrillation (AF) with rapid ventricular response. He was known as a case of AF for almost 10 years without adequate rate control or anticoagulant therapy. On the radiography of chest, significant cardiomegaly with cardiothoracic ratio (CTR) of 92% was noticed (Fig. 1). A transthoracic echocardiography revealed a remarkably huge right atrium (RA), moderate right ventricular (RV) dilation and dysfunction, malcoapted tricuspid valve (TV) with annulus diameter of 7.5 cm and severe tricuspid regurgitation with peak pressure gradient of 36 mmHg. Although the anterior leaflet of TV appeared mildly deformed, regarding the distance between the hinge points of the septal leaflet of the TV and the anterior mitral valve leaflet (up to 7.6 mm in absolute; 4.1 mm/m²), negligible distance between the posterior TV leaflet offset and mitral annulus and the absence of atrialized RV, the diagnosis of Ebstein anomaly was unlikely (Fig. 1, supplementary Fig. 2, videos 1, 2). The measured RA diameters in the apical four chamber view in end systole were 13.6 cm × 19.5 cm with estimated volume of 1960 ml (1059 ml/m²) based on single plane area-length method. The left ventricle (LV) and left atrium had small size with severely reduced LV ejection fraction. Surprisingly, the RA volume of 3500 ml (1892 ml/m²) was measured in contrast-enhanced cardiac CT scan with three dimensional volumetric study (Fig. 1).

…