Coronary Dominance in Fetuses of Manipuri Origin

Abstract

The cardiovascular system is the first organ system of an embryo to reach a functional state. The heart is supplied by the right and left coronary arteries which arise from the ascending aorta. The artery giving off the posterior interventricular branch is defined as the dominant artery. Materials and method: Thirty fetal hearts ranging from gestational age of 17 wks to 40 wks are studied. Results and observation: Right dominance in 70%, left dominance in 20% and co dominant in 10%. Myocardial bridges are also a common finding in the course of the arteries. Conclusion: This study provides potentially useful information for the preoperative evaluation of the newborn. The right and left coronary arteries arise from the ascending aorta. The right coronary artery gives off the conus artery as its first branch. The right marginal artery is long enough to reach the apex in most hearts. As the right coronary approaches the crux of the heart, it normally produces one to three posterior interventricular branches (occasionally there are none). One, of them lies in the interventricular groove as the posterior interventricular artery. The left coronary divides into two or three main branches. The anterior interventricular artery is commonly described as the continuation of left coronary artery. The left diagonal artery reach the rounded (obtuse) left border. The circumflex artery, comparable to the anterior interventricular artery in calibre, curves left in the atrioventricular groove, continuing round the left cardiac border into the posterior part of the groove and ending left of the crux in most hearts, but sometimes continuing as a posterior interventricular artery. 3 The artery giving off the posterior interventricular branch is defined as the dominant artery. In a balanced circulation, branches of both arteries run in or near the posterior interventricular groove. 4 The dominant artery is usually the right in 67% of the population. In approximately 15% of hearts the left coronary artery is dominant in that the posterior interventricular artery is a branch of the circumflex artery. There is co-dominance in approximately 18% of people, in which branches of both the right and left coronary artery reach the crux of the heart and give rise to branches that course in or near the posterior interventricular groove.