Anomalous Left Coronary Artery Originating from the Right Sinus of Valsalva with a Transseptal Course

Anomalous origin of the left main coronary artery (LMCA) from the right sinus of Valsalva with a transseptal course is a rare congenital coronary anomaly with variable clinical implications. We report the case of a 76-year-old man with heart failure caused by severe aortic regurgitation and significant functional mitral regurgitation. Preoperative coronary angiography failed to identify the LMCA ostium, but cardiac computed tomography revealed an anomalous LMCA originating from the right sinus of Valsalva and traversing the interventricular septum (initially downward and then upward), a pattern known as the “hammock sign”, consistent with the transseptal course of an anomalous LMCA. The patient underwent successful surgical aortic valve replacement and mitral annuloplasty, without coronary intervention. Intraoperative findings confirmed anomalous coronary anatomy. This case highlights the importance of a detailed preoperative coronary assessment in patients with valvular heart disease to identify coronary anomalies that may influence surgical planning.