Contribution to the study of the blood supply of the sinus node in horses

Abstract

The arterial blood supply of the sinus node has been studied in 50 horses (25 males and 25 females). The sinus node was nourished by the ramus proximalis atrii sinistri and ramus distalis atrii dextri in 29 (58.0% ± 7.0) of the examined cases; by the ramus proximalis atrii sinistri and ramus intermedius atrii dextri in 18 (36.0% ± 6.8) of the examined pieces; by the ramus proximalis atrii sinistri, ramus intermedius atrii dextri and ramus distalis atrii dextri in 1 (2.0% ± 2.0) of the examined hearts; by the ramus proximalis atrii dextri and ramus distalis atrii dextri in 1 (2.0% ± 2.0) of the examined organs; by the ramus distalis atrii dextri in 1 (2.0% ± 2.0) of the examined specimens. Arterial anastomoses were observed in 5 cases between collaterals from rami proximalis atrii sinistri and proximalis atrii dextri, 1 case; between collaterals from rami proximalis atrii sinistri and distalis atrii sinistri, 1 case; between collaterals from rami proximalis atrii sinistri and intermedius atrii dextri, 1 case; between collaterals from rami proximalis atrii sinistri and distalis atrii dextri, 1 case; between collaterals from rami distalis atrii dextri and intermedius atrii dextri, 1 case. There was no sexual influence in the pattern of the blood supply to the sinus node.