The Coronary Anomaly: Right Coronary Artery Originates from the Mid Left Anterior Descending Artery

ABSTRACT: The most common coronary anomaly is the left circumflex artery (LCX) arising from the proximal right coronary artery (RCA). This variant is benign. The anomalous RCA often originates from the left sinus or from the proximal of the left main coronary artery. This case report presents a single coronary artery that is the RCA originating from the mid left anterior descending artery. The case is rare. We discuss how to make a accurate diagnosis and how to administer appropriate treatment.

J INVASIVE CARDIOL 2010;22:E166–E167

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Case Report. A 72-year-old woman presented with a history of progressive angina pectoris of 3 months duration. She had a ten-year history of diabetes mellitus and hypertension. We performed the coronary angiogram through the transradial approach. Coronary angiography showed a nonobstructed left main coronary artery (LMCA) and diffuse left anterior descending (LAD) artery disease extending from the mid to the distal segment. There was a long lesion in the mid segment of left circumflex artery (LCX). We placed the catheter to the right sinus to examine but the right coronary artery (RCA) could not be visualized. Where is the RCA? We the found the origin of the RCA at the mid LAD artery, and it was patent (Figures 1, 2, 3). Based on these findings, the decision was made to proceed with percutaneous coronary intervention (PCI) to the mid and distal LAD and LCX. A 2.5 × 30 mm Endeavor (Medtronic Corporation, Minneapolis, Minnesota) stent was implanted at the distal LAD, and a 3.0 × 29 mm Firebird (MicroPort Medical Corporation, Shanghai, China) stent, crossing over the RCA artery, was deployed at the mid LAD at 14 atm, jailing the wire in the RCA. The mid LAD stent appeared to be underexpanded, so it was postdilated with a 3.0 × 12 mm Quantum Maverick RX balloon (Boston Scientific Corporation, Natick, Massachusetts) up to 14 atm. Then the BMW was used to cannulate the LCX, a 3.0 × 29 mm Firebird (MicroPort Medical Corporation, Shanghai, China) stent was deployed at the mid LCX at 14 atm. Finally a good angiographic result was observed and the RCA was not influenced after PCI procedure of LAD (Figure 4). Discussion. The most common coronary anomaly is the left circumflex artery arising from the proximal right coronary artery (RCA).This variant is benign. The anomalous RCA often originates from the left sinus or from the proximal of LMCA. It would course between the aorta and the pulmonary artery to its normal position. In the RAO view, the RCA will be seen head-on, as a dot anterior to the aorta. This coronary anomaly is associated with symptoms of myocardial ischemia, particularly when the RCA is dominant.¹ The coronary angiogram showed no RCA from the right sinus where the RCA was, as they had the data from the left injection. Cases reporting an RCA originating from the mid of LAD, is rare. The anomalous artery, seen in the left ventriculogram, may course in front of the pulmonary artery (anterior course). In this type, the anomalous RCA crosses the free wall of the right ventricle and in front of the pulmonary artery.^2,3 In the LAO view, the RCA is seen like a letter C. To focus on the ostial segment, a caudal angulation is needed. A cranial angulation would help to show the bifurcation, origin and the course of the PDA. In this case, the anomalous RCA is not dominant, and the RCA is not influenced after the PCI procedure of LAD was performed. In addition to coronary angiography, transesophageal echocardiography⁴ and contrast-enhanced electron-beam tomography⁵ have also been recommended to detect the anomalous coronary artery, but they are too costly for screening large populations. Accurate diagnosis is prognostically important because of fatal events associated with the interarterial pathway. The cardiologist must pay attention to the anomalous coronary artery, especially a single coronary anomaly. To our knowledge, this is the first published report of abnormal RCA originating from the mid of LAD. It is a rare case in our hospital.

References

1. Serota H, Barth CW IIi Seuc CA, et al. Rapid identification of the course anomalous coronary artery in adults: The “dot and eye” method. Am J Cardiol 1990;65:891–898. 2. Husaini SN, Beaver WL, Wilson IJ, et al. Anomalous RCA arising from leftstem. Cathet Cardiovasc Diagn 1983;9:407–409. 3. Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diag 1990;21:28–40. 4. Gaither NS, Rogan KM, Stajduhar K, et al. Anomalous origin and course of coronary arteries in adults：Identification and improved imaging utilizing transesophageal echocardiography. Am Heart J 1991;122:69–75. 5. Ropers D, Moshaqe W, Daniel WG, et al. Visualization of coronary artery anomalies and their anatomic course by contrast-enhanced electron beam tomography and three-dimensional reconstruction. Am J Cardiol 2001;87:193–197.

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From the First Affiliated Hospital of Tsinghua University, Beijing, China. The authors report no conflicts of interest regarding the content herein. Manuscript submitted January 7, 2010, provisional acceptance given January 15, 2010, final version accepted March 2, 2010. Address for correspondence: Dr. Qin Xuguang, 0712, Doctorate, Huaxin Hospital, Department of Cardiology,1st street No.6, Jiuxianqiao, Wangjing West Road, Chaoyang, Beijing 100016, China. E-mail: qin-xuguang0712@163.com