Arterial supply of the sinoatrial node: a CT coronary angiographic study.

We aimed to investigate the variances in especially the origin, course and termination of the sinoatrial node (SAN) artery in this study, using coronary CT angiography. The coronary CT angiography images of 251 patients (190 men and 61 women; age range, 20–82 years; mean age, 54.4 ± 13.6 years) were retrospectively analyzed. The SAN artery (arteries) in each case was named according to a special nomenclature with regard to their origin, course and termination. The sinoatrial node was being vascularized by a single artery in 241 (96%) cases and by two arteries in 10 (4%) cases. It was arising from RCA in 139 (55.4%) cases, from LCX in 99 (39.4%) cases, from the aorta in 2 (0.8%) cases, and from the bronchial artery in 1 (0.4%) case. The mean diameter of the SAN arteries was 2.3 mm. The mean distance between the origin of the SAN artery from RCA and the RCA ostium was 16.2 mm, from LCX and the origin of LCX was 19.3 mm. Frequency of the atrial branch was 35.9%. S-shaped SAN artery is determined in 51 (20.3%) cases. Coronary CT angiography is considerably effective in depicting the various vascularization types of SAN.