Anomalous Intercoronary Communication with Unidirectional Flow in the Absence of Obstructive Coronary Artery Disease: A Case Report.

Large intercoronary communications in the absence of obstructive coronary artery disease constitute a very rare coronary artery anomaly in which there is a readily visible connection between the 2 coronary arteries with a unidirectional or bidirectional blood flow; consequently, this anomaly may be misinterpreted as a functioning collateral vessel, indicative of an unrecognized proximal coronary artery occlusion. In contrast to collateral vessels that are seen in the presence of critical coronary artery stenosis and total occlusions, these arterial communications are vessels that are single, extramural, straight, and large in diameter. Myocardial ischemia could result from the coronary steal phenomenon by a unidirectional intercoronary communication. Herein, we describe a 57-year-old female with chest pain who was found in coronary angiography to have a single large intercoronary channel between the posterolateral branch of the right coronary artery and the distal left circumflex artery with a unidirectional flow.