The heart’s hidden blueprint: a rare variant of coronary artery origin from the right coronary cusp

Single coronary artery (SCA) is a rare congenital anomaly in which a solitary coronary ostium supplies the entire myocardium. While often benign, certain anatomical variations can predispose patients to ischemia or sudden cardiac death. We report the case of a 51-year-old male with chest pain and normal ECG findings. Coronary computed tomography angiography (CCTA) revealed a rare variant of SCA in which the LAD, LCX, and RCA each arose separately from the right coronary sinus, without a common trunk. The LAD followed a pre- pulmonic course, while the LCX coursed retro-aortically. A significant mid-RCA stenosis was noted. This case illustrates a rare Lipton RIII-type SCA variant with independent origins of all major coronary branches. Recognition of such anomalies is critical, as certain courses may carry a higher risk of ischemia or sudden cardiac death. CCTA remains essential for accurate, noninvasive anatomical assessment. The relevance of CCTA in clinical decision-making was highlighted by the identification of this anatomy, which affected therapy by directing revascularization strategy and avoiding high-risk interventional techniques.