[Specifics of the blood supply of the sinoatrial node]

The present study aims to identify the heart nodal system blood supply sources and especially those of the sinoatrial node. It included 50 unpreserved and preserved human hearts from subjects of both sexes (40 males and 10 females) aged 12 to 68, of Romanian (42) and non-Romanian origin (8). The used denominations are those recommended by DiDio & Wakefield, based on splitting of the atrial walls into four quadrants (right and left, both anterior and posterior) which are further divided into three parts (medial, middle and lateral). We used special dissection techniques and plastic mass injections followed by corrosion. Our results confirm the opinion shared by most authors, in favour of the predominance of the origin of sinoatrial node artery from the right coronary artery. The sinoatrial node was supplied by a unique source represented by the right coronary artery in 37 cases (74%) and by the circumflex artery in 8 cases (16%), and by a double source represented by two branches of the right coronary artery in 2 cases (4%) and of both coronary arteries in 3 cases (6%). The direct arterial branches to the sinoatrial node were represented mainly by the right anteromedial atrial artery with origin from the right coronary artery level with the medial third of the right anterior quadrant of the atrial wall. From the left coronary system, the left anteromedial artery is the one responsible with the sinoatrial node supply; the source is the circumflex artery and its origin is the medial third of the left anterior quadrant. Contrary to DiDio et al., we found in addition to the mainly unilateral blood supply, the bilateral one. We didn't find any case with a sinoatrial node artery originating from the trunk of the left coronary artery, or with an extracardiac origin. We may state there are no significant differences of the origin and distribution of the sinoatrial node artery related to sex or country of origin. Thus, we cannot fully confirm the theories about the influence of the general variation factors on the arterial origin. The atherosclerotic or thrombotic obstruction of the sinoatrial node artery may induce severe heart rhythm disturbances or even sudden death.