Origin of the left anterior descending coronary artery from the right coronary artery is a well‐described but rare congenital coronary anomaly. In this report, we describe two cases in which the mid left anterior descending coronary artery is connected to the right coronary artery through an intraseptal connecting vessel, while the proximal left anterior descending coronary artery originates normally from the left main coronary artery. This previously unreported pattern suggests partial persistence of the peritruncal ring, which occurs during normal embryologic development of the coronary circulation. Even though it is classically described as an epicardial structure, the vascular pattern in our cases suggests that the peritruncal ring may have an intramural segment in some individuals. Copyright © 1989 John Wiley & Sons, Ltd.
