Coronary artery anomaly

Coronary artery anomalies are variations of the coronary circulation, affecting <1% of the general population. Symptoms include chest pain, shortness of breath and syncope, although cardiac arrest may be the first clinical presentation. Several varieties are identified, with a different potential to cause sudden cardiac death.

Physiology of coronary arteries

Coronary arteries are vessels supplying blood and nutrients to the heart muscle (myocardium).

Coronary arteries arise from ostia, openings of the aorta (the largest artery in the human body) at the upper third or middle third of the sinuses of Valsalva (the first part of the big pipe coming off the main pumping chamber). The walls of coronary arteries consist of three layers: the tunica intima or inner layer (possible site of lipid deposits and fibrosis, during life), the tunica media (a smooth muscle layer whose tone is modulated by the nervous system, influencing vessel diameter and resistance) and adventitia (where nervous endings are located). Normally, the initial portion of coronary arteries lies onto the external surface of the heart (epicardium) where fat deposits tend to form during life.

In normal anatomy, three essential coronary arteries are identified: right coronary artery (RCA), left anterior descending artery (LAD) and left circumflex artery (LCx). LAD and LCx usually originate from the bifurcation of a common vessel known as left main trunk or left coronary artery (LM or LCA).

Coronary arteries are identified according to the myocardial territory they feed:

1) the LAD supplies the anterior interventricular septum and anterior left ventricular free wall;

2) the LCx supplies the posterolateral left ventricular free wall;

3) the RCA supplies the right ventricular free wall;

In fact, despite a certain degree of variability in coronary artery anatomy among individuals, there is greater consistency in the regions of the heart that are supplied by the different coronary arteries.