Single Coronary Artery in the Context of Vascular Disease: Anatomy, Development, Multimodality Imaging, and Clinical Interpretation

Background: Single coronary artery (SCA) is a rare and anatomically heterogeneous congenital coronary anomaly in which the entire coronary circulation arises from a single aortic ostium. Its clinical significance depends on the ostial and proximal morphology, coronary course, associated coronary disease, symptoms and, where indicated, functional findings. Methods: PubMed/MEDLINE was searched with free-text terms from 24 December 2025 to 12 July 2026 and rerun on 9 August 2026; relevant reference lists were screened manually. Results: SCA-specific evidence consisted mainly of case reports, small series, and descriptive imaging studies. A single ostium or Lipton code does not fully describe the relevant anatomy. Reports should state whether a true common trunk is present, map the course and supplied territory of each major branch, and document proximal morphology and acquired coronary disease. Coronary computed tomography angiography (CCTA) is central to anatomical assessment in many adults. Functional testing is most informative when the method addresses the suspected mechanism. Conclusions: SCA should be interpreted by integrating detailed anatomy, symptoms, coexisting coronary disease and, when appropriate, mechanism-matched functional findings. The three-domain structure used here supports reporting and multidisciplinary discussion, but it is not a validated risk model or treatment algorithm. Prospective evidence on SCA-specific outcomes and management remains limited.