A Case of Unroofed Coronary Sinus with Coronary Sinus Orifice Atresia: Use of Multimodality Imaging

Abstract

A 44-year-old woman visited our clinic because of sudden onset pain in both lower extremities. After admission, computed tomography (CT) was performed and revealed occlusion of both popliteal arteries and renal infarction in the left kidney. Transthoracic echocardiography (TTE) revealed rheumatic mitral stenosis (Figure 1A). In the apical view of TTE and on transesophageal echocardiography, we identified a huge dilated coronary sinus (CS) (Figure 1B) and detected large defect between the dilated CS and left atrium (LA) (Figure 1C, Movie 1). On contrast echocardiography with agitated saline, the right atrium (RA) was filled with air bubbles, but not the dilated CS, and then the right ventricle was filled with air bubbles later (Figure 1D). This finding showed no persistent left superior vena cava (PLSVC), which was supported by the CT imaging finding (Figure 2A). On CT, a huge dilated CS was observed, showing no communication with the RA, which suggested CS orifice atresia (Figure 2B). On real-time three-dimensional (3D) echocardiography in the en face view of the LA, an ovoid-shaped defect was found between the CS and the LA, posterior to the mitral valve (Figure 3A). After horizontal rotation of the image, no communication between the CS and the RA was visible, which suggested CS orifice atresia (Figure 3B). The patient was discharged after stabilization. Unroofed coronary sinus (UCS) is a spectrum of cardiac anomalies in which part or all of the common wall between the CS and the LA is absent.1) Seventy-five percent of the UCS is associated with PLSVC.1) Atresia of the RA orifice of the CS is rare. Most cases of CS orifice atresia are associated with an alternative exit for coronary venous blood return, such as a small PLSVC, large thebasian vein, or CS canal defect, like in the present case.2) Myocardial ischemia is unlikely as long as an alternate exit exists for CS blood.3) Multimodality imaging such as, TTE, transesophageal echocardiography, contrast echocardiography, 3D echocardiography, CT, or magnetic resonance imaging is needed to diagnose this anomaly, like in the present case. In case of operation, the flow of CS blood should be retained. Deaths due to myocardial ischemia after ligation of a PLSVC were reported.4)