An Unusual Case of Dilated Coronary Sinus: Case Report and Clinical Implications

BACKGROUND The presence of a dilated coronary sinus (CS) assessed by echocardiography (TTE) is highly suggestive of inferior or superior vena cava anomalies, in the absence of a shunt. The most frequent finding is the persistence of a left superior vena cava (LSVC): well-known feature to electrophysiologists. Abnormal inferior vena cava (IVC) drainage is another cause of CS dilatation. CASE SUMMARY An 83-year-old woman presented with heart failure symptoms, atrial fibrillation with rapid ventricular rate and a dilated CS assessed by TTE. Atrioventricular (AV) node ablation was considered given the poor efficacy of a rate-control strategy. Cardiac computed tomography (CT) revealed a double superior vena cava with a LSVC draining directly into the dilated CS. Single-lead pacemaker implantation was performed using a right-side vascular access with no technical difficulties. An aborted AV node ablation procedure was due to the impossibility of getting to the right atrium. Fluoroscopy and CT imaging at second-look analysis confirmed the diagnosis of an abnormal IVC with an agenesia of its supra-hepatic segment directly drained into the CS. DISCUSSION Our clinical case illustrates an unusual and rare double venous abnormality: both LSVC and IVC directly drained into the CS and were responsible for its massive dilatation.