Original Research Article DOI: 10.18231/2394-2126.2017.0046 Indian Journal of Clinical Anatomy and Physiology, April-June, 2017;4(2):185-189 185 Anatomical study of right coronary artery and its variations – Cadaveric study A.K. Manicka Vasuki 1,* , M. Jamuna 2 , Deborah Joy 3 , M. Nirmala Devi 4 , K. Radhika 5 1,3,5 Assistant Professor, 2 Professor & HOD, 4 Associate Professor, Dept. of Anatomy, *Corresponding Author: Email: vasukikalyan01@gmail.com Abstract Introduction: Knowledge of the normal and variant anatomy and anomalies of coronary circulation are vital component in the management of coronary artery disease. Any coronary artery disorder may reduce the blood supply to the heart and may lead to Myocardial infarction and death. The aim of the study was to identify right coronary artery branching pattern and its variations. This may indirectly affect the patient’s prognosis. This study describes the presence of normal arterial pattern and variations of right coronary artery in fifty heart specimens. Materials and Method: This study was carried out on fifty formalin fixed adult human cadaveric heart specimens of both sexes. Visceral pericardium and subepicardial fats were removed. The right coronary artery and its branches were carefully dissected and followed till their termination. Results: The right coronary artery was found to be arising from pulmonary trunk in three heart specimens in our study. Third coronary artery was found in one specimen. Sinu atrial nodal artery was arising from right coronary from right coronary artery in 94% and from left coronary artery in 6% Right dominance was observed in 35(70%) specimens. Fistula between right coronary artery and pulmonary artery was found in one specimen. Conclusion: Branching pattern of right coronary artery is important for interpretation of coronary angiography and surgical revascularization of myocardium. Keywords: Coronary artery, Sinu – atrial nodal artery, Fistula, pulmonary artery Introduction Coronary arteries represent the only supply to the myocardium. The two main coronary arteries, right and left coronary arteries arise from ascending aorta. Right coronary artery arises from right anterior aortic sinus and left coronary artery arises from left posterior aortic sinus. Patency of left coronary artery is vital for sufficient perfusion of the heart. The left coronary artery is responsible for irrigation, not only of most of the left ventricle, but also considerable portion of right ventricle. (1) Right coronary artery runs between pulmonary trunk and right auricle and then runs downwards and is divided into two segments. First segment runs along the right border of the heart up to inferior border of heart. It gives right conus artery and supplies infundibulam of the right ventricle. If the right conus artery arises separately from the aortic sinus, then it is called as Third coronary artery. The second segment runs up to the apex as right marginal artery and supplies right ventricle. Sometimes it may runs in the posterior interventricular groove and may give rise to Posterior interventricular branch. Hence according to the origin of posterior interventricular artery, the coronary artery dominance has been considered. Right coronary artery ends in the crux by anastomosing with circumflex artery. It supplies the right atrium, right ventricle, atrioventricular septum and part of left ventricle. Sinu atrial nodal artery may arise as atrial rami from initial segment of right coronary artery in 65% of the cases and from circumflex artery in 35% of the cases. Atrioventricular nodal artery arises as first septal ramus of posterior interventricular artery in 90% of the cases and 10% from the left coronary artery. (2) Numerous studies on the variations of the arteries have been reported, but still it is better to study them further with respect to their clinical significance. Coronary anomalies are a poorly understood topic in modern cardiology. Clinicians should be aware of such anomalies because some of them may produce sudden death. The incidence of congenital coronary artery anomalies is 5–6%. By definition, the term anomalous or abnormal is used to define any variant form observed in less than 1% of the general population. (3) The aim of the study is to identify the normal pattern of the coronary arteries and its variations. Though the modern techniques of revascularisation and coronary bypass surgeries are available, the knowledge about the anatomy of coronary arterial pattern and its variations are important for the cardiologists and cardio – thoracic surgeons. Materials and Method Fifty formalin fixed heart specimens of both sexes with intact coronary arterial pattern were studied in Anatomy department, PSG IMS & R, Coimbatore. The right coronary artery and its branches were carefully dissected out till their termination and were analysed for normal and abnormal patterns of coronary arteries.