Venous System of the Myocardium with Special Reference to the Conduction System

Myocardial veins and sinusoids of the right atrioventricular junction of the heart were studied in serial section, and their relations to the common conduction bundle and nodal tissues were anatomically demonstrated by wax model reconstructions. It is suggested these venous channels may well explain the complete, but transient, bundle block of children observed in certain toxic diseases. On the other hand, the same sinusoids functioning as capillaries may nourish the bundle tissues in older decades, thus explaining the low incidence of bundle block in cases of gradual coronary occlusion. The possible role of these vessels to the intercoronary circulation is discussed.