Coronary arteries of anomalous origin are rare. The clinical importance of coronary artery anomaly may vary between asymptomatic harmless conditions and hazardous lesions, which may even lead to sudden cardiac death (SCD). Coronary anomalies may be classified into 2 groups according to their anatomical characteristics: anomalies of origin and distribution and anomalies of termination. Coronary artery originating from contralateral sinus of Valsalva carries the highest risk [1] . Anomalous origin of the right coronary artery (RCA) from the left sinus of Valsalva (LSOV) has been found in 6% - 27% of the patients with coronary anomalies [2] and in 0.02% - 0.17% of coronary angiogram. The treatment schedule of anomalous origin RCA complicated with coronary artery diseases (CAD) included drug conservative therapy, PCI and surgical correction or/and coronary artery bypass graft. However, past studies have indicated the subjects of RCA anomalous origin lived to adulthood but developed CAD and did not show superfluous advantages from surgical correction [3] [4] . It is noteworthy that anomalies cause technical problems during coronary angiography as well as during percutaneous transluminal coronary angioplasty (PTCA). We are presenting a case of an old patient who experienced myocardial infarction as a result of chronic total occlusion in RCA which had anomalous origin of left coronary cusp.

A 71 years old female patient, hypertensive and nondiabetic, admitted to our hospital for the severe chest pain along with exertional dyspnea. She has been diagnosed with inferior wall myocardial infarction (IWMI) six mo- nths back.

Electrocardiogram was suggestive of old IWMI. Echocardiography evaluation revealed concentric left ventricular (LV) hypertrophy, normal resting LV systolic function (ejection fraction = 60%), no regional wall motion abnormality, mitral annular calcification, normal pulmonary arterial pressure and type I diastolic dysfunction. Coronary angiography showed dominant RCA (type-III vessel) with anomalous origin from left coronary sinus having chronic total occlusion in proximal portion (Figure 1) and normal left anterior descending artery and left circumflex artery (Figure 1). We planned to perform PTCA for RCA in view of chronic total occlusion.

Anomalous right coronary ostium was selectively engaged by using 3.5 6F IKARI catheter launcher guiding catheter (Terumo, Heartrail II) using right trans-femoral approach. Chronic total occlusion of proximal-RCA was crossed with 0.014" × 180 cm Fielder XT guidewire (Asahi Intecc Co., Ltd., Japan) with the support of microcatheter (Figure 2). A contralateral injection was given through collaterals to fill distal RCA.

Fielder XT wire guide wire was then exchanged with 0.014" × 190 cm BMW guide wire (Abbott Vascular, USA). Pre-dilatation of the lesion was carried out by 2.5 × 15 mm Maverick-II balloon (Monorail) at 6 - 8 atm pressure for 30 sec. However, post balloon check angiogram showed 30% - 40% residual lesion. A 3.5 × 32 mm drug eluting stent, Supralimus core^TM (Sahajanand Medical Technologies Pvt Ltd., India), was deployed in mid RCA at 9 - 14 atm pressure for 30 sec. Another Supralimus core^TM stent (Figure 3) was deployed in proximal RCA overlapping the previous stent. In stent dilatation was done using 3.5 × 15 mm Quantum Maverick II balloon (Monorail) at 12 - 26 atm pressure for 30 sec.

Check angiogram showed well placed stent with TIMI III flow (Figure 4) and non residual stenosis or dissection or thrombus. The stay of patient in the was uneventful and he was discharged from the hospital along with clopidogrel and aspirin (Clopivas-AP, 150 mg) for 1 year as well as metoprolol (Metpure-XL, 50 mg) and ramipril (Cardace, 2.5 mg).

The incidence of coronary artery anomalies varies from 0.3% to 1.3% [5] -[7] . However, with the development of cardiac imaging techniques the coronary anomalies have been increasingly reported nowadays. Topaz et al., reported the incidence of coronary anomalies 0.61% and also concluded anomalous origin of RCA as the most common anomaly in 13,010 patients with the incidence of 0.38% [6] .

So far a variety of anomalous origins of RCA have been reported in the literature. According to previous studies, the most common anatomic site of anomalous RCA originated mainly at four locations: LCS, antetheca of the aortic wall, supracristal plane above the right coronary sinus (RCS) and left coronary system [8] -[11] . Praharaj, T., et al., reported anomalous origin of RCA from left sinus of the valsalva [12] . Elbasan, Z., et al., reported a case of anomaly of RCA with LAD [13] .

Coronary intervention of RCA is technically challenging in patients with an anomalous artery. It demands a high degree of awareness and complete evaluation of the coronary artery anatomy and distribution in order to avoid complications.

A study by S. Turkmen et al., reported that branching of RCA from LSV was 0.10% comprising 8% of the total anomalies present [1] . Most of the anomalies are considered benign. Similar case was observed in our patients. A patient was observed with chronic total occlusion in anomalous RCA with Type I diastolic dysfunction. We performed PCI with excellent angiographic results.

It is very important, how we evaluate the anatomic site of anomaly of RCA. Selection of cannulation is based on various factors such as the angiographic results of LCA and occurrence frequency of anomalous RCA ostium. Any blinding operations may increase the dosage of the contrast agent, operation time, and additional radioactive damage and even increase the possibility of coronary artery dissection or aortic dissection and other serious complications [14] . Patients of anomalous RCA underwent selective PCI should go through a test of contrast enhanced CT angiography (CTA) to affirm originated sites, anatomic route and whether they are complicated with other congenital malformations. CTA is also advantageous in selecting the therapy and auxiliary PCI procedures [15] -[18] .

Proper selection and skillful manipulation of guide catheter are the key factors for successful PCI of anomalous RCA [19] . Guide catheter selection should be done on the basis of origin site, anatomic ostium, and characteristics of lesion, vascular conditions, travel route, supporting requirement and other comprehensive considerations [20] .

Manipulating skills must be needed during the PCI. Due to the anomalous anatomic origin of RCA, guide catheters are inevitably more difficult to be sound coaxialilty. Under such situation, using wisely a method of guiding the PCI wire “gone with the flow” and stepping it to the distal-RCA are more beneficial and even smo- othens our work. Multi-wire anchoring technology can be used to lead the guide catheter to the appropriate place

and complete the process of stent installment.

In summary, a case of chronic total occlusion of anomalous right coronary artery originating from left coronary sinus successfully underwent PCI.