[Heart conduction system in the human in light of personal research]

A new model of the atrioventricular junction was developed by Anderson et al, of which each element has clinical significance and requires more specific research into its morphology and topography. Observations were carried out on materials consisting of 200 human hearts of both sexes of various ages (from 16 weeks of fetal life to 97 years of age). Histological slides were stained by Masson's method in Goldner's modification. It was concluded that the atrioventricular node consisted of two layers in all groups of examined hearts: cells of the compact area and transitional cells. With age, these cells change their morphology, especially in the transitional layer. Morphologically, within the atrioventricular bundle were differentiated. The topography of the atrioventricular node is dependent on the age of the examined heart. As much as in human adults it is found entirely within the triangle of Koch, in fetal and children's hearts its elements of its left branch were found in the false chordae tendinae of the left ventricle. The above observations suggest that in the case of younger hearts the triangle of Koch does not represent an absolute margination for the elements of the conductive system of the heart, which in the case of cardiac surgical procedures and ablations can in some percent, be the cause of iatrogenic complications.