CASE REPORT Ramus Circumflexissimus—A Rare Coronary Anomaly Detected by Coronary Computed Tomography Angiography Femke M. van de Sandt, MD,* Robert K. Riezebos, MD, † and Victor P.M. van der Hulst, MD, PhD † *Department of Cardiology, Hofpoort Ziekenhuis, Woerden and † Department of Cardiology, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands ABSTRACT We present a case of L-1 type solitary (left) coronary artery that was detected with coronary computed tomography angiography and confirmed by invasive coronary angiography in a female patient with atypical chest pain. Solitary coronary artery anomalies are rare. The L-1 subtype is thought to be a benign type. Key Words. Cardiac Computed Tomography; Coronary Angiography; Coronary Artery Anomaly; Single Coronary Artery; L-1 Type Single Coronary Artery; Coronary Computed Tomography Angiography A 52-year-old female presented to the emer- gency department with chest pain provoked by emotion. An acute coronary syndrome was excluded electrocardiographically and biochemi- cally. Echocardiography was unremarkable and ischemia testing was inconclusive. Coronary com- puted tomography angiography was performed, revealing a solitary coronary artery originating from the left sinus of Valsalva. This single coro- nary artery had a normal takeoff and proximal course, dividing into an anterior descending branch and a circumflex branch. After providing the posterior descending artery, the superdomi- nant left coronary artery continued in the right posterior atrioventricular groove, supplying marginal branches to the right ventricle and ter- minating near the right sinus of Valsalva. A right coronary ostium was absent (Figure 1). Invasive coronary angiography confirmed these findings (Figure 2A and B). Coronary artery anomalies are encountered in 0.6–1.3% of patients referred for invasive coro- nary angiography. 1 Contrast-enhanced computed tomography offers additional possibilities to detect coronary anomalies, with the advantages of being noninvasive and providing three- dimensional imaging of the coronary arteries in relation to their surroundings. A rare subset of coronary artery anomalies are the single coronary artery (SCA) anomalies. Isolated SCA anomalies (in the absence of associated cardiovascular anomalies) have a reported incidence of 0.044– 0.066%. 1,2 In 1979, A useful classification of SCA anomalies was proposed by Lipton et al. in 1979, and later modified by Yamanaka and Hobbs. 1,3 Our Figure 1. Three-dimensional, reconstructed coronary computed tomography angiography images showing the solitary left coronary artery, its “ramus circumflexissimus” extending to right ventricular territory. LAD, left anterior descending; PDA, posterior descending artery; RCxCx, ramus circumflexissimus. 1 © 2011 Wiley Periodicals, Inc. Congenit Heart Dis. 2011;••:••–••