A Single Coronary Artery From the Left Coronary Sinus: The Continuing Conundrum.

It is extremely rare to come across a single coronary artery during routine interventional cardiology practice. The incidence of single coronary arteries increases across congenital heart diseases. We report an extremely rare case of a single coronary artery arising from the left coronary sinus in an octogenarian presenting with anterior wall non-ST elevated myocardial infarction (NSTEMI) secondary to atherosclerotic occlusion of the proximal left main coronary artery (LMCA). It is often difficult to selectively engage a single coronary artery due to anomalous origin from the sinus; nonselective coronary sinus injection often suffices in visualizing the single coronary trunk dividing into left and right coronary arteries besides demonstrating the associated route and atherosclerotic anomalies.