166 Jung-Jin Lee, et al. A B Fig. 3. (A) Pre-intervention image: Right coronary angiogram shows significant narrowing of proximal RCA and middle RCA. (B) Post intervention image: Stents were successfully deployed in the proximal RCA and middle RCA lesion, and the final angiogram showed an optimal result. RCA, right coronary artery. Fig. 4. Left coronary angiogram revealed no significant narrowing of LCA which was originated from the posterior sinus of Valsalva. LCA, left coronary artery. level until it normalized. On the third hospital day, MDCT revealed an anomalous origin of the RCA from the ascending aorta above the left sinus of Valsalva and the LCA from the posterior sinus of Valsalva (Fig. 2). The RCA coursed between the ascending aorta and the pulmonary trunk, and significant narrowing was observed at the junc- tional point between the portion wrapped around the aorta, pulmonary artery and the free portion of the proximal RCA, and middle RCA. On the seventh hospital day, a second trial of coronary angiography was performed. After con- Yonsei Med J Vol. 50, No. 1, 2009 firming the absence of a right coronary artery ostium on the right sinus of Valsalva, the anom- alous RCA was selectively cannulated with a 6Fr AL1 guiding catheter. The coronary angiography revealed a tubular eccentric proximal RCA with 95% stenosis and a thrombus, and a diffuse, irre- gular middle RCA with up to 95% stenosis (Fig. 3). The lesions were crossed with a Hi-torque PILOT 0.014 guidewire (Guidant). The AL1 catheter offered stable seating and superior back-up support. A 2.5 × 20 mm Ryujin plus (Terumo) balloon dilata- tion was performed at the proximal RCA and middle RCA lesions. A 3.5 × 16 mm TAXUS stent (Tax, Boston scientific, Natick, MA, USA) was successfully deployed in the proximal RCA lesion and a 3.0 × 28 mm TAXUS stent (Boston scientific) was deployed in the middle RCA lesion. A final angiogram revealed that the procedure was successful (Fig. 3). A left coronary angiogram per- formed using a 5Fr AR2 catheter showed no signi- ficant narrowing of the LCA, which originated from the posterior sinus of Valsalva (Fig. 4). The patient was discharged on the tenth day. DISCUSSION The prevalence of an anomalous origin of a cor- onary artery from the opposite sinus (ACAOS) is unclear. A recent prospective angiographic study