The anatomy and development of normal and abnormal coronary arteries

Abstract

At present, there is significant interest in the morphology of the coronary arteries, not least due to the increasingly well-recognised association between anomalous origin of the arteries and sudden cardiac death. Much has also been learnt over the last decade regarding the embryology of the arteries. In this review, therefore, we provide a brief introduction into the recent findings regarding their development. In particular, we emphasise that new evidence, derived using the developing murine heart, points to the arterial stems growing out from the adjacent sinuses of the aortic root, rather than the arteries growing in, as is currently assumed. As we show, the concept of outgrowth provides an excellent explanation for several of the abnormal arrangements encountered in the clinical setting. Before summarising these abnormal features, we draw attention to the need to describe the heart in an attitudinally appropriate manner, following the basic rule of human anatomy, rather than describing the cardiac components with the heart in the "Valentine" orientation. We then show how the major abnormalities involving the coronary arteries in humans can be summarised in terms of abnormal origin from the pulmonary circulation, abnormal aortic origin, or fistulous communications between the coronary arteries and the cardiac cavities. In the case of abnormal aortic origin, we highlight those malformations known to be associated with sudden cardiac death.

Coronary Artery Anomalies in Animals

“…Connection of the coronary arteries to their appropriate aortic valvar sinuses occurs late in development, after closure of the interventricular septum and coincident with development of the aortic root and semilunar valves [ 8 ]. Early in development, the coronary arteries develop as layered epithelial cells filled with erythrocytes (called sinusoids or blood islands), which proliferate and conjoin to form a network of vascular channels [ 9 ].…”

“…The coronary arteries are eventually connected to the aortic valvar sinuses, allowing antegrade flow from aorta through the coronary vascular bed [ 9 ]. The process by which the coronary arteries connect to the aorta is an area of uncertainty with recent reports based upon murine data describing endocardial strands growing from the aortic root as the outflow tracts are undergoing septation [ 8 ]. Previously, it was thought that the developing epicardial coronary arteries grew toward and then into the developing aortic root [ 9 ].…”

“…In the normal mammalian heart, the aortic valve sinuses are adjacent (facing) the right and left aspects of the pulmonary valve while the third sinus is non-adjacent. To maintain appropriate anatomical terminology in a congenitally-malformed heart where the position of the great vessels may be altered, the aortic sinuses are therefore named as if they were viewed from the non-adjacent aortic sinus and facing the pulmonary valve giving a right aortic sinus or cusp, a left aortic sinus or cusp, and a non-adjacent sinus or cusp [ 8 ]. In the vast majority of animal hearts, the two coronary ostia are located within the left and right aortic valvar sinuses adjacent to the pulmonary trunk ( Figure 1 ).…”

Novel approaches to study coronary vasculature development in mice

“…These data serve as proof of principle of the value of whole-heart clearing coupled with fluorescence reporter systems in high-resolution evaluation of coronary artery development. Given the considerable current interest in coronary artery anatomy and development, due to the role of coronary artery anomalies in sudden cardiac death in humans (Spicer et al, 2015) and their remodeling in mouse models of myocardial infarction (Miquerol et al, 2015), the Cx40:GFP mouse model could pave the way for detailed-down to a single-cell resolution-analysis of the origin, course, and remodeling of coronary arteries to establish the relationships between anatomy and clinical events.…”

The Spectrum of Congenital Heart Disease with Transposition of the Great Arteries from the Cardiac Registry of the University of Padua

“…With the advent of the arterial switch operation for the repair of complete TGA, the presence of coronary anomalies has become more relevant ( 34 – 40 ). In the hearts of our Collection, even if in presence of anomalous origin, all the coronary arteries arose from the sinuses adjacent to the pulmonary trunk.…”