Type IV Dual Left Anterior Descending Artery Associated with Anomalous Origin of the Left Circumflex Coronary Artery

From the Right Coronary Artery: A Case Report

ABSTRACT: Dual left anterior descending coronary artery (LAD) originating from the left main stem and the right coronary artery (RCA) (Type IV dual LAD) is a very rare coronary artery anomaly. Association of this anomaly with the anomalous origin of the circumflex artery from the RCA is a very rare occurrence. In this report, we describe a patient presenting with acute lateral wall myocardial infarction who subsequently was found to have this coronary anomaly. J INVASIVE CARDIOL 2008;20:669–670 Adult coronary anomalies are not very common and are usually casual findings of diagnostic angiographic studies. The incidence of these anomalies has been reported to be between 0.29% and 1.34% of the general population.1–3 Coronary artery anomalies may involve anomalies of origin and course, anomalies of intrinsic coronary arterial anatomy, anomalies of coronary termination and anomalous collateral vessels.4 Herein, we report an unusual case of anomalous coronary artery circulation who presented with acute lateral wall MI and underwent successful percutaneous coronary intervention. Case Report. A 55-year-old male was admitted to our hospital because of chest pain. The physical examination was completely normal at presentation. The electrocardiogram revealed ST-segment elevation in leads I and aVL. He was successfully reperfused by intravenous thrombolytic therapy after which both ST-segment elevations and chest pain resolved. He underwent a coronary angiography on the second day following infarction. Selective left coronary angiography revealed only a short left anterior descending artery (LAD), which terminated at the proximal segment of the anterior interventricular groove after giving rise to one major septal and three diagonal branches (Figure 1). There was a critical stenosis at the LAD just proximal to the third diagonal and a major septal artery. Selective right coronary angiography showed a nondominant right coronary artery (RCA) from which both the circumflex (Cx) and the LAD originated. The LAD reached the distal segment of the anterior interventricular groove by making a cranial anterior loop that indicated an anterior free-wall course.5 The Cx reached the left atrioventricular groove by using a retroaortic course.5 After predilatation with a 2.5 x 16 mm balloon, the lesion on the LAD was successfully stented using a 2.5 x 12 mm bare-metal stent. Discussion. Anomalous origin of the Cx from the right coronary sinus (RCS) or the proximal RCA is one of the most common forms of coronary artery anomalies. It has been reported in 0.17–0.45% of patients undergoing selective coronary angiography.1,6,7 In contrast, Type IV dual LAD is a very rarely seen anomaly.8–10 In this anomaly there are two LAD arteries: one originates from the left main coronary artery and lies in the proximal anterior interventricular sulcus, and the other one takes origin from the RCA and lies in the distal anterior interventricular sulcus.8 In their original study that defined dual LAD types, Spindola-Franco et al found only 2 patients with this anomaly among 2140 patients.8 Similarly, Rigatelli et al reported only 2 cases among 5100 angiographic examinations.9 A recent study reported only 3 cases with Type IV double LAD anomaly in 70,850 adult patients undergoing coronary angiography.10 In our case, a Type IV dual LAD was observed in association with a Cx arising from the proximal RCA. This type of a combination of two distinctly defined coronary anomalies has previously been reported only twice in the English literature.11,12 The first of these two cases presented with acute inferior wall myocardial infarction and the infarct-related artery was found to be the posterior descending artery and the patient was treated medically.11 The second case underwent mechanical aortic valve replacement and coronary artery bypass grafting.12 Our case presented with acute lateral wall myocardial infarction and infarct-related artery was found to be the proximal LAD, which was successfully stented. To the best of our knowledge, our report represents the first case in which percutaneous intervention successfully opened an occluded artery in this type of extraordinarily rare coronary anomaly.

1. Click RL, Holmes DR Jr, Vlietstra RE, et al. Anomalous coronary arteries: Location, degree of atherosclerosis and effect on survival — A report from the Coronary Artery Surgery Study. J Am Coll Cardiol 1989;13:531–537.
2. Yamanaka O, Hobbs RE. Coronary artery anomalies in 126,595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn 1990;21:28–40.
3. Kardos A, Babai L, Rudas L, et al. Epidemiology of congenital coronary artery anomalies: A coronary arteriography study on a central European population. Cathet Cardiovasc Diagn 1997;42:270–275.
4. Angelini P, Velasco JA, Flamm S. Coronary anomalies: Incidence, pathophysiology, and clinical relevance. Circulation 2002;105:2449–2454.
5. Ishikawa T, Brandt PW. Anomalous origin of the left main coronary artery from the right anterior aortic sinus: Angiographic definition of anomalous course. Am J Cardiol 1985;55:770–776.
6. Topaz O, DeMarchena EJ, Perin E, et al. Anomalous coronary arteries: Angiographic findings in 80 patients. Int J Cardiol 1992;34:129–138.
7. Chaitman BR, Lesperance J, Saltiel J, Bourassa MG. Clinical, angiographic, and hemodynamic findings in patients with anomalous origin of the coronary arteries. Circulation 1976;53:122–131.
8. Spindola-Franco H, Grose R, Solomon N. Dual left anterior descending coronary artery: Angiographic description of important variants and surgical implications. Am Heart J 1983;105:445–455.
9. Rigatelli G, Docali G, Rossi P, et al. Validation of a clinical-significance-based classification of coronary artery anomalies. Angiology 2005;56:25–34.
10. Tuncer C, Batyraliev T, Yilmaz R, et al. Origin and distribution anomalies of the left anterior descending artery in 70,850 adult patients: Multicenter data collection. Catheter Cardiovasc Interv 2006;68:574–585.
11. Tutar E, Gulec S, Pamir G, et al. A case of type IV dual left anterior descending artery associated with anomalous origin of the left circumflex artery in the presence of coronary atherosclerosis. J Invasive Cardiol 1999;11:631–634.
12. Bitigen A, Erkol A, Oduncu V, et al. Atherosclerosis in type IV 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.