A Rare Coronary Anatomy Comprising Dual (Type IV) Left Anterior Descending Arteries and an Anomalous Left Circumflex Artery from the Right Coronary Artery

ABSTRACT: We present the case of a rare coronary anomaly in a 64-year-old male who presented with exertional angina. The right coronary artery (RCA) was dominant, giving origin proximally to an anomalous left circumflex (LCX) artery and a left anterior descending (LAD) artery which supplied the conventional mid and distal LAD territory. The left main artery (LM) arose from the left coronary sinus and branched into a large first septal and an intermediate artery. There was associated non-critical atherosclerotic disease. We report this because of the rare division of the LAD area of supply by arteries from both coronary sinuses (dual LAD) with an anomalous LCX also arising from the proximal RCA. The clinical implications are discussed. J INVASIVE CARDIOL 2011;23:126–127 ————————————————————

Case Report

A 64-year-old male with an old inferolateral myocardial infarction (MI) underwent coronary angiography for new-onset angina. It showed a long left main artery from the left sinus branching into a large first septal, which was the end of the left anterior descending artery (LAD), and an intermedius branch (Figure 1). From a proximal dominant right coronary artery (RCA) from the right coronary sinus, there emerged an anomalous LAD and a left circumflex artery (LCX) (Figure 2). This anomalous LAD supplied the mid and distal LAD territories, complementing the other LAD. A computerized tomographic angiogram (CTA) was done to see the proximal courses of the anomalous LCX and LAD in relation to the great arteries (Figures 3 and 4). While the anomalous LCX followed a retro-aortic course to reach the left atrioventricular groove, the anomalous LAD coursed anterior to the right ventricular outflow tract to reach the anterior interventricular groove. Hence, neither of the anomalous arteries had a malignant inter great artery course. There was non-critical triple-vessel disease and, hence, he was advised medical follow up. Coronary artery anomalies have a reported incidence of 0.2% to 1% of routine angiographic studies.¹ Anomalous origin of the LCX and LAD from the right sinus,^1,2 a second LAD from the right sinus³ and dual LADs with anomalous origin of the circumflex artery⁴ have been rarely reported. Four subtypes of dual LAD arteries have been described.⁵ They are best studied by CTA. Severe atherosclerotic disease with dual LAD has been reported.⁶ Dual LADs have been categorized into four angiographic types according to the origin, course and termination of the short and long LADs.⁷ Our patient can be categorized as type IV. He had only non-critical atherosclerotic disease which did not match the degree of his symptoms. This is clinically possible if the anomalous vessels, proximally, have an inter great artery course. Also, vasospasm in anomalous coronary arteries has been implicated as a mechanism of angina.⁸ The good tradeoff is that the binary distribution of the LAD limited the extent of ischemic insult to the anterior wall.

References

1. Taghipour HR, Dadjou Y, Mafi AR, Moharamzad Y. A very rare case of single coronary artery anomaly, with left anterior descending and left circumflex arteries originating separately from the proximal right coronary artery. J Card Surg 2008;23:67–69.
2. Bartorelli AL, Capacchione V, Ravagnani P, Pepi M. Anomalous origin of the left anterior descending and circumflex coronary arteries by two separate ostia from the right sinus of valsalva. Int J Cardiol 1994;44:294–298.
3. Talanas G, Delpini A, Casu G, et al. A double left anterior descending coronary artery emerging from the right Valsalva sinus: A case report and brief literature review. J Cardiovasc Med (Hagerstown) 2009;10:64–67.
4. Aggarwal PP, Kazerooni EA. Dual left anterior descending coronary artery: CT findings. AJR Am J Roentgenol 2008;191:1698–1701.
5. Kimbiris D. Anomalous origin of the left main coronary artery from the right sinus of valsalva. Am J Cardiol 1985;55:765–769.
6. Bitigen A, Erkol A, Oduncu V, et al. Atherosclerosis in type 4 dual left anterior descending artery and anomalous aortic origin of the left circumflex artery in association with rheumatic valve disease: A case report. Heart Surg Forum 2007;10:E276–E278.
7. Manchanda A, Querishi A, Brofferio A, et al. Novel variant of dual left anterior descending coronary artery. J Cardiovasc Tomogr 2010;4:139–141.
8. Oshima M, Takizawa A, Watanabe K, et al. A case of dual origin of the left anterior descending artery from the left and right coronary arteries with variant angina. Kokyu To Junkan 1993;41:667–671.
9. Namboodiri N, Ajit Kumar V, Tharakan J. A rare type of left anterior descending artery distribution demonstrated by multi slice cardiac computerised tomography in a patient with anterior wall infarction. J Invasive Cardiol 2008;20:367–369.

———————————————————— From the Department of Cardiology, Lancashire Cardiac Centre, Victoria Hospital, Blackpool, United Kingdom. The authors report no conflicts of interest regarding the content herein. Manuscript submitted September 21, provisional acceptance given October 7, 2010, final version accepted October 15, 2010. Address for correspondence: Dr. Pradeepto Ghosh, Lancashire Cardiac Centre, Victoria Hospital, Whinney Heys Road, Blackpool, United Kingdom FY38NR. E-mail: pradeeptoghosh@yahoo.com