Anatomical basis for the separation of four cardiac zones in the walls of human heart ventricles.

The coronary vessels of 70 human hearts were visualized postmortem by injection of the coronary arteries with a X-ray opaque substance (for angiographic studies) or with a low viscosity resin (to obtain vascular casts). Analysis of the data suggests a new anatomical systematization of the vascularization of the myocardial tissue of human heart ventricles: it can be divided into four zones each having a different origin of the arterial vessels. These four components of the heart ventricles are the antero-septal (AS), postero-septal (PS), left-lateral (LL), and right-lateral (RL) zones. They correspond to the territories of the anterior interventricular branch of the left coronary artery (AS zone), of the posterior interventricular branch of the right coronary artery (PS zone), of the left circumflex artery (LL zone), and of the right coronary artery (RL zone) up to the origin of the posterior interventricular artery. This systematization of the arterial heart ventricles in zones offers a balanced division of the myocardial tissue, since each of the four zones occupied about one fourth of the total volume of the ventricles. In our samples, the most common distribution of segments in the wall of heart ventricles was the following: 16 segments in the AS zone, 11 segments in the PS zone, 5 segments in the LL zone, and 4 segments in the RL zone. The separation of four zones in the walls of heart ventricles, each of them made up of different segments, may be helpful in the understanding of the pathophysiology of myocardial ischemia, and also in the choice of surgical strategies to treat aneurisms of the heart ventricle wall.