Morphological and Morphometric Study of Coronary Sinus in North Indian Population

Coronary sinus (CS) is the largest vein draining the blood from heart. It is a muscular tube of about 2 cm to 3 cm length and 1 cm in caliber. It has become a clinically important structure through its role in providing access for different cardiac procedures viz., biventricular pacing, arrhythmia ablation and for deployment of an array of cardiac devices.

To study the location, shape, length and width of CS including its left atrial muscular coverage in 50 cadaveric hearts.

The present study comprised of 50 adult human apparently normal formalin fixed cadaveric hearts belonging to either sex obtained from the Department of Anatomy, Government Medical College, Amritsar, India. Location and shape of CS were noted, external and internal lengths of the CS were measured with the help of a thread and Vernier caliper. Width of CS was measured at three levels; at the beginning, at the point of entry of Middle Cardiac Vein (MCV) and at termination in right atrium. The walls of CS were examined to note whether they were covered by the muscles of left atrium or not. Descriptive analysis was done to calculate range, mean and Standard Deviation (SD) by using Statistical Package for Social Science (SPSS) 17.0.

CS was located in the posterior atrioventricular sulcus in 98%. Two shapes; funnel in 82% and tubular/cylindrical in 18% were observed. External length of coronary sinus ranged from 20.5 mm to 58.78 mm (mean 38.22±8.6 mm) and internal length ranged from 16.28 mm to 49.6 mm (mean 34.48±8.9 mm). Maximum width of coronary sinus was at its termination (9.61±2.6 mm) and it was covered by muscles of left atrium in 96% of hearts.

CS is a constant structure in cardiac venous anatomy but its location, shape, length and width are variable. Knowing these variations can help cardiac surgeons especially during cardiac resynchronization therapy, ablation and defibrillation.