Unroofed coronary sinus detected by 2D/3D echocardiography in a patient referred to catheter ablation for atrial fibrillation.

A 67-year-old female visited our echo lab for a preoperative screening exam before radiofrequency catheter ablation for atrial fibrillation. Transthoracic echocardiography revealed abnormal color flow signal in the right atrium, and following 2D/3D transesophageal echocardiography proved partial type of unroofed coronary sinus. Absence of associated congenital abnormalities was ruled out by Doppler and contrast echo examinations. Surgical findings confirmed exactly the same anatomical abnormalities as preoperative 2D/3D echocardiography. Echocardiography plays an important role in finding unexpected underlying cardiac diseases in patients who are referred to arrhythmia clinics. In the present case with atrial fibrillation, we could accurately diagnose an unroofed coronary sinus syndrome during preoperative transthoracic and transesophageal echocardiography prior to planned radiofrequency catheter ablation. <Learning objective: Radiofrequency catheter ablation therapy for atrial fibrillation has been greatly developed in recent years. Echocardiography plays an important role in the diagnosis of underlying cardiac diseases in patients who are referred to arrhythmia clinics. We could clearly visualize partial type of unroofed coronary sinus by 2D/3D echocardiography in a patient who was planned to undergo radiofrequency catheter ablation, and then could contribute to the proper therapeutic management for the rare congenital heart disease.>.