Prevalence of the Anomalous Aortic Origin of a Left Coronary Artery from the Right Coronary Sinus and Posterior Course: detection by Transthoracic Echocardiography in an Unselected Ambulatory Population

Background: Transthoracic echocardiography (TTE)  may detect  the origin and/or  abnormal course of  coronary epicardial  vessels.  We describe a novel TTE  pattern specific for  the anomalous origin of a left coronary vessel from the right coronary sinus and a posterior course and its prevalence in an unselected population of ambulatory patients. Methods:  We prospectively studied 3692 consecutive patients who performed  a routine TTE.  In these subjects we looked for an abnormal finding that we found associated with the anomalous aortic origin of a coronary artery. Computed Tomography of the Coronary Arteries (CTCA)  was performed in each suspected case. Results: We found a TTE aspect suggestive for a coronary anomaly and a retroaortic course in 16 subjects out of the 3298 studied (0,48%).  CTCA invariably confirmed the presence of the  anomaly. In 15 out of the 16 patients the left coronary vessel originating from the right coronary sinus (RCS) was the left circumflex artery (LCX).  In  the remaining  patient  the anomalous vessel was the left main coronary artery . Conclusions: We found a  TTE sign specific for a particular kind of  coronary anomaly.  By using TTE it is possible to detect the retroaortic course of an anomalous left coronary vessel originating from the RCS. This  pattern was found to be rare  but pathognomonic for this specific kind of congenital anomaly.  The ability to detect this specific kind of coronary anomaly by TEE may be relevant to the patient in some cases  thus representing useful clinical  information.