Open ended circulation pattern: a rare case of a protective coronary artery variation and review of the literature.

Persistent intercoronary communications, forming the so-called open ended coronary circulation pattern, are rare findings of coronary angiography. A case of intercoronary connection between the left anterior descending artery (LAD) and the right coronary artery (RCA), with an obstructive lesion, and no evidence of myocardial infarction is presented. This is an exceptional variant, only 20 cases of which were found in the literature. The potential protective role of this anomaly against occlusive coronary artery disease is discussed and similar reports are reviewed.