Anatomical Reasons for the Discrepancies in Atrioventricular Block after Inferior Myocardial Infarction with and without Right Ventricular Involvement

The incidence of arrhythmias after acute myocardial infarction of the inferior wall varies with the affected segment and increases when there is right ventricular involvement. This paper provides a clear review of the blood supply to the conduction system and gives an anatomic explanation of that supply. We dissected 20 human hearts after anterograde and retrograde injection of latex. In every heart, we dissected the conduction system and its blood supply. Retrograde perfusion enabled proper injection of the atrial vessels that originate at the beginning of the coronary trunks. We describe the 4 main arteries that supply blood to the conduction system. The classic concept included the atrioventricular node artery and the 1st septal artery. To that we add Kugel's artery and the right superior descending artery. The incidence of arrhythmias after acute myocardial infarction of the inferior wall is greater when the occlusion of the coronary trunk is at or near the origin. This is due to the existence of the right superior descending artery, which is given off by the right coronary trunk less than 1 cm from the origin. The arrhythmias caused by the occlusion of the circumflex artery are due to the existence of Kugel's artery, which displays a peculiar anastomotic pattern.