Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 13 2 2018 05 23 80 83 EN Ahmet Taha Alper Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, İstanbul, Turkey. Mert İlker Hayıroğlu Department of Cardiology, Haydarpasa Sultan Abdulhamid Han Training and Research Hospital, Istanbul, Turkey. Hakan Barutça Department of Radiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, Kadiköy, Istanbul, Turkey. Ahmet İlker Tekkeşin Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, İstanbul, Turkey. Ceyhan Türkkan Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital, İstanbul, Turkey. 2017 08 22 2018 02 26 The coronary sinus, whose electrical features play an important role in cardiac arrhythmias, is the integral part of the cardiac venous system. Here we describe a 67-year-old male patient with congestive heart failure who was referred to our hospital after the failure of the first cardiac resynchronization therapy defibrillator (CRT-D) implantation. During the cannulation of the coronary sinus, the separate orifice of the posterior cardiac vein was demonstrated by the retrograde filling of the coronary sinus via contrast injection into the posterior cardiac vein. Due to the serious tortuosity of the coronary venous sinus, a multipolar left ventricular lead was implanted using the separate ostium of the posterior cardiac vein. In our patient, the posterior cardiac vein directly drained into the right atrium. At 3 months’ follow-up with the CRT-D, he was asymptomatic (New York Heart Association functional class I). https://rhythm.tums.ac.ir/index.php/jthc/article/view/765 https://rhythm.tums.ac.ir/index.php/jthc/article/download/765/658