ABSTRACT
Background: The coronary sinus is a dilated venous channel opening into the right atrium of the heart. The coronary venous system has gained importance in recent years for electrophysiological procedures like arrhythmia ablation, biventricular pacing and implantation of cardiac pacemakers. The present study aims to study the formation and tributaries of coronary sinus and also the morphology of thebesian valve. Materials and Methods: 30 formalin fixed cadaveric hearts available in the department of Anatomy, Dhanalakshmi Srinivasan Medical College and Hospital, Perambalur, Tamil nadu, was used for the study. The formation and tributaries of coronary sinus were noted. The length of coronary sinus in millimeters was measured from the union of great cardiac vein and left marginal vein upto the opening of the coronary sinus in the right atrium with vernier calipers. The width of the coronary ostium in the right atrium was measured in millimeters with vernier calipers. Results: In 93.33% specimens the coronary sinus was formed by the union of great cardiac vein and left marginal vein. In 3.33% specimens it was formed by the union of great cardiac vein and posterior vein of left ventricle, and in 3.33% specimens it was formed by the union of great cardiac vein and oblique vein of left atrium. The left marginal vein was absent in 2 specimens and small cardiac vein was absent in 1 specimen. The mean length of coronary sinus was 54.98 + 12.2mm. The mean width of coronary sinus ostium was 9.35 + 3.24mm. The Thebesian valve was present in 93.33% specimens and it was semilunar in shape. Conclusion: The knowledge of coronary sinus anatomy will be helpful during electrophysiological procedures. KEY WORDS: Coronary Sinus, Cardiac Veins, Thebesian Valve, Coronary Ostium, Electrophysiological Procedures.