The Atrio-Ventricular Node Artery in the Human Heart

Abstract

The atrioventricular node artery is a major contributor to the arterial supply of the atrioventricular conducting pathway and is an important vessel in the pathogenesis of heart block. The terminal ramifications of this artery were studied in detail by serial sectioning techniques in 50 human infant hearts. The artery provided branches to the posterior interventricular septum in all hearts (100%) and to the interatrial septum in 22 hearts (44%). The vessel supplied the atrioventricular node in 45 hearts (90%) but it terminated before reaching the node in five (10%). It supplied the penetrating bundle in 32 hearts (64%). Alternative sources of arterial supply to the atrioventricular conducting path way include: the first septal branch of the left anterior descending coronary artery; the descending septal artery; and anterior atrial branches. Although the arterial supply to this region of the heart is variable, it is possible to make hypothetical predictions of conducting tissue involvement in myocardial in farction of various types.