Contribution to the study of the blood supply of the sinus node in thoroughbred horse

Abstract

The arterial blood supply of the sinus node has been studied in 50 thoroughbred horses (26 males and 24 females). The sinus node was nourished by the ramus distalis atrii dextri in 22 (44.0% ± 7.0) of the examined hearts; by the ramus distalis atrii dextri and ramus proximalis atrii sinistri in 21 (42.0% ± 7.0) of the examined specimens; by the ramus intermedius atrii dextri and ramus proximalis atrii sinistri in 5 (10.0% ± 4.2) of the examined organs; by the ramus distális atrii dextri and ramus intermedius atrii dextri in 2 (4.0% ± 2.8) of the examined pieces. The ramus proximalis atrii sinistri, reaching or not the terminal furrow it sends systematically 1 (16.% ± 5.2) or 2 (84.0% ± 5.2) contributions to interatrial septum, place where the presence of nodal tissue is discussable. We did not see any evident anastomosis between the implied vessels in the arterial blood supply of the sinus node. Sex did not influence tre blood supply pattern to the sinus node.