The prevalence of coronary artery anomalies at conventional coronary angiography is approximately 1%. However, a higher incidence of coronary artery anomalies is observed in young victims of sudden death (4%–15%) when compared with adults
An anomalous origin of the right coronary artery (RCA) from the left coronary sinus (AORL), with an interarterial course as the most common coronary anomaly
AORL with an interarterial course between the aorta and the pulmonary trunk may be associated with myocardial ischemia and may be the cause of myocardial infarction (MI), sudden cardiac death, arrhythmia, and syncope
The hemodynamic significance of AORL with an interarterial course differs according to the location of the anomalous RCA ostium, because the hemodynamic significance might depend on the degree of RCA ostium compression and/or the interarterial RCA segment. An RCA ostium located above the pulmonary valve (high interarterial course) would be more compressed, because blood is forced into the aorta and pulmonary artery during systole, resulting in simultaneous distention of these vessels, which in turn may lead to compression of the interarterial segment between these great vessels. This phenomenon can be aggravated during exercise. On the other hand, the right ventricular outflow tract (RVOT) contracts during systole, so an RCA ostium below the pulmonary valve (low interarterial course) would be less compressed between the aorta and RVOT
https://pubs.rsna.org/doi/10.1148/radiol.11110823
