Venous circulation of the human cardiac conduction system.

Abstract

summARY The venous bed ofthe sinuatrial node in 25 human hearts and the atrioventricular conduction system in 50 human hearts were investigated after injection into different veins of the heart. Blood is drained from the sinuatrial node in two directions; that from the intermediate and upper parts of the node blood is directed upwards, draining into the junctional area ofthe superior vena cava with the right atrium. From the intermediate and the lower parts ofthe node the venous return is directed downwards, draining directly into the right atrium between the musculi pectinati.The venous return from the ventricular conduction system is drained by three routes. The main route from the atrioventricular node and the atrioventricular bundle passes into the thebesian vein, which opened in 78 per cent of the cases studied into the right atrium next to the coronary sinus. The other route from the node and bundle is via a vein which accompanies the atrioventricular nodal artery, draining eventually into the middle cardiac vein. The third route takes venous blood from the lower part of the atrioventricular bundle and is drained to the tributaries of the great cardiac vein, interconnecting with the branches of the above two veins. The venous return from the ventricular bundle-branches is drained into the oblique septal veins.The venous drainage of the conduction system was described by Geraudel (1928), Abraham (1964), and Kennel and Titus (1972), all of whom thought that blood was drained from the atrioventricular node by thebesian veins into the right ventricle. Truex and Schwartz (1951) also described the veins of the atrioventricular conduction system, but they regarded them as dilated sinusoids and maintained that they played an important role in facilitating the influence of toxins upon the conduction system.In the present paper an attempt will be made to supplement and enlarge the data concerning the localisation of venous drainage of different segments of the conduction system and their interconnections. Subjects and methodsThe venous drainage of the sinuatrial node has been visualised in 25 human hearts (13 men, 12 women) by injecting the thebesian veins opening into the superior vena cava in the region of the node and opening between the musculi pectinati of the right atrium. The veins draining the region of the atrioventricular node and atrioventricular bundle have been visualised in 50 hearts (27 men, 23 women) by injecting various veins, namely those Received for publication 9 May 1979 opening into the upper part of the great cardiac vein, those opening into the upper part of middle cardiac vein, and, finally, by injecting thebesian veins opening into the right atrium. The substances used for injection included a solution of Indian ink in 2 per cent gelatin, a pigment Seabondorange suspension in 2 per cent gelatin, and a radiopaque substance, Mikropaque.The regions of the sinuatrial nodes obtained from 16 hearts and those ofthe antrioventricular nodes and atrioventricular bundles obtained from 25 hearts w...

Abnormally Enlarged Singular Thebesian Vein in Right Atrium

“…Although not proven they are also suggested to be able to maintain the myocardial blood supply in episodes of coronary arterial occlusion [ 7 ]. The TV has been known to drain the atrioventricular node after which they commonly open into the right atrium, 1 cm anteriorly or posteriorly to the ostium of the coronary sinus [ 9 ]. The ostium of the abnormally enlarged TV in our reported case opened 4 mm superoanteriorly to the ostium of the coronary sinus.…”