Origin of the sinoatrial and atrioventricular nodal arteries in South Indians: an angiographic study.

BACKGROUND To study the arterial supply of the conducting system and its correlation with the dominance of the coronary arteries in the South Indian population. OBJECTIVE To determine angiographically the origins of the sinoatrial nodal artery (SAna) and atrioventricular nodal artery (AVna) in Indians. METHODS The study included 300 consecutive patients (114 females, 186 males; mean age, 55 years) living in the southern coastal region of India, who underwent coronary angiography either for the symptoms of chest pain, angina pectoris or positive Treadmill Test. The angiograms contained both coronary arteries (right and left) in the right and left anterior oblique position. The origin of SAna and AVna from the coronary arteries was observed and correlated with the arterial dominance. RESULTS The SA (sinoatrial) node was supplied by the right coronary artery (RCA) in 53% of the cases, by the circumflex (Cx) branch of left coronary artery (LCA) in 42.66%, and by both coronary arteries in 4.33% of cases. The AV (atrioventricular) node was also more often supplied by the RCA (72.33% of cases) than by the Cx branch of the LCA (27.66%), and surprisingly in none of the cases was this node supplied by both coronary arteries. CONCLUSION The results of the present study may help cardiac surgeons, particularly in surgeries related to certain valvular disorders, due to the proximity of the nodal branches to the valve complex.