[Intramural blood vessels in the AV segment of the human heart conduction system]

We have investigated the intramural blood vessels of the A-V segment in the conductive system of 20 human hearts using the method of light microscopy. The results of our study have shown that the A-V segment of the conductive heart muscles in human hearts has an abundant vascularisation. We have found the greatest density of the intramural net in the dorsal part of the A-V node; this density of blood vessels decreased toward the Hiss' bundle. After comparing these results with the earlier findings in the study of the intramural net in the S-A system we have found that A-V segment of the conductive heart system has a poorer blood supply in regard to S-A system. We have also found that the intramural net of blood vessels is weaker in the adjacent ventricular parts and in the interventricular septum. It cannot be said that there exists any surface vascular zone subepicardial, middle and deep sub-endocardiac--in the A-V segment of the conductive system of human heart.