Single coronary artery--a rarity in the catheterization laboratory: case report and current review.

A single coronary artery is a rare anomaly but has been associated with sudden cardiac death. A 73-year-old man with atypical chest pain and exercise-induced ischemia arising from a single coronary artery with the left main coronary stem originating from the proximal right coronary artery and passing posterior and inferior to the aortic root is described. The exact three-dimensional course was not reliably established by coronary angiography but was clearly demonstrated by contrast-enhanced electron beam tomography. The most reasonable hypotheses for myocardial ischemia and sudden death emphasize the accentuation of the angle at the origin of specific distribution patterns of an anomalous coronary artery that may compromise coronary blood flow. Other mechanisms such as coronary spasm and hypoplasia are also discussed. The literature review provides a historic overview and insights into the developmental history of the anomaly, classification of the various morphological patterns, clinical significance and therapeutic approaches.