Anomalous course of coronary arteries

Anomalous course of a coronary artery is a type of congenital coronary artery anomaly. It may represent a benign and incidental finding, but can also be a malignant course predisposing patients to life-threatening myocardial ischemia or arrhythmias, depending on where the artery runs. 

Clinical presentation

The majority (approximately 80%) of anomalous coronary artery courses are benign and asymptomatic. However, on rare occasions, it can result in ischemia, arrhythmias or sudden death. Most symptomatic patients present at a young age.

Pathology

The coronary artery may pass between the aorta and the main pulmonary artery, representing a so-called interarterial course. It may be associated with a "slit-like" orifice in which an acute angle course at the ostium is more prone to occlusion. During physical activity, the artery may be compressed, and the flow within it may be compromised. The presence of a "slit-like" orifice or intramural course of the coronary artery within the aortic wall is more predictive of adverse outcome than the interarterial course alone.

There are four common courses for an anomalous coronary artery arising from the opposite sinus ^4,5:

• malignant course
  • interarterial (i.e. between the aorta and the pulmonary artery): this is the most dangerous as it carries a high risk of sudden cardiac death 
• benign course
  • retroaortic
  • prepulmonic
  • septal (subpulmonic)

Treatment and prognosis

Treatment of anomalous coronary arteries is controversial. Mainly patients with a benign course rarely need surgical treatment. Symptomatic patients with an inter-arterial course may require surgical "re-implantation" of the anomalous coronary artery or "de-roofing" if an intramural course is present.