Aspects of blood supply of the atriumventricular node and trunk of the atriumventricular fascicle, components of the cardiac conducting system were studied. Thirty female hearts of Girolando crossbred bovines, with ages varying between 36 and 48 month-old were utilized. They were dissecated, intervening previous injection of the right and left coronary arteries with coloured solution of Neoprene latex 450, and posterior fixation in aqueous solution of 15.00% formaldehyde, by immersion. The atriumventicular node was irrigated, isolatedly or in association, by the first septal branch of interventricular paraconal branch (3.33%), distal branch of the left atrium (6.66%), septal branch of the right coronary artery (46.66%), proximal branch of the right atrium (76.66%) and by the right ventricular branch. (76.66%). The trunk of atriumventricular fascicle was irrigated, isolatedly or in association, by the first septal branch of interventricular paraconal branch (3.33%), right ventricular branch (60.00%), proximal branch of the right atrium (60.00%) and more often by the septal branch of the right coronary artery (70.00%). Arterial anastomoses were present in 76.66% of the sample, and commonly they formed circuits around the margins of the cardiac conducting system.
Bovines; Atriumventricular node; Trunk of the atriunventricular node; Vascularization
