The posterior ventricular branches of the coronary arteries in the human heart.

OBJECTIVE To describe the trajectory of the posterior ventricular branches of the coronary arteries in the epicardial adipose tissue, and to propose a new criterion for analyzing the distribution of these branches, according to the traditional classification, to determine the predominance or balance of the coronary arteries in the arterial supply to the heart. METHODS Forty hearts obtained from autopsies of adults were dissected and fixed in a formol solution. The posterior face of each ventricle was divided into 8 approximately equal areas for the morphological classification of the coronary circulation. The following 3 traditional types were considered: A) right dominance, B) balanced, and C) left dominance. The number, diameter, and terminal areas of the posterior ventricular branches in the epicardium were analyzed. RESULTS The following branches and respective frequencies were found: left marginal branch -- 100%; posterior left ventricular branches: lateral -- 75%, intermediate -- 82.5%, and medial -- 87.5%; interventricular posterior branch -- 95%; posterior right ventricular branch: medial -- 40%, intermediate -- 32.5%, and lateral -- 40%; posterior diagonal branch of the right ventricle -- 17.5%; right marginal branch -- 95%. In regard to dominance, the following values were found: dominance of the right coronary artery -- 62.5%; balanced type -- 25%; and dominance of the left coronary artery -- 12.5%. CONCLUSION The method adopted allowed a more precise classification of the types of coronary artery distribution found. The right coronary artery dominance type was the most prevalent, followed by the balanced type and the left coronary artery dominance.