ABNORMAL ORIGIN OF THE LEFT CIRCUMFLEX CORONARY ARTERY FROM THE RIGHT CORONARY ARTERY

Transcription

1 ABNORMAL ORIGIN OF THE LEFT CIRCUMFLEX CORONARY ARTERY FROM THE RIGHT CORONARY ARTERY Antonio Fuertes, M.D.,* Mario Trivellato, M.D.,** and Jeff Z. Brooker, M.D.*** INTRODUCTION Primary anomalies of the coronary circulation are uncommon. Alexander et al.1 have reported an incidence of primary coronary anomalies of 2.85 per thousand in 18,950 autopsies completed in the Los Angeles County Hospital between 1940 and The advent of initially nonselective and currently selective coronary angiography has made a definite contribution toward the diagnosis and classification of primary coronary artery anomalies. The importance of appreciating primary coronary artery anomalies at the time of study has more than academic significance in the light of our interest in coronary artery bypass graft surgery. Accordingly, four patients recently seen at the St. Luke's Episcopal and Texas Heart Institute Clinic with the same anatomic anomaly of their coronary arteries are briefly presented and illustrated. CASE 1-A farmer from Florida had two previous myocardial infarctions, one in 1968 and one in At the time of admission to St. Luke's Hospital, the patient had no angina. Physical examination revealed a slight left ventricular lift and the presence of a gallop rhythm. The electrocardiogram showed anteroseptal myocardial infarction and elevation of the ST segment suggestive of left ventricular aneurysm. On January 7, 1974, the patient underwent cardiac catheterization and selective coronary angiography. The right coronary artery was dominant and shared a common ostium from the right aortic sinus of Valsalva with the left circumflex artery (Figure 1). The left main coronary artery arose normally from the left sinus of Valsalva. The left ventriculogram displayed an aneurysm of the lateral wall. Since the patient was experiencing no angina, he was discharged on medical treatment. CASE 2-A 52-year-old untreated hypertensive college president first noticed exertion-provoked upper back and neck discomfort approximately two years prior to The patient had undergone selective coronary angiography on February 1, 1974, in Denver because of a striking family history of coronary artery disease and a positive treadmill test. At that time, near-total occlusion of the left anterior descending artery was demonstrated. Also shown was the anomalous origin of the left circumflex coronary artery sharing a common ostium with the right coronary artery on the right sinus of Valsalva of the aorta (Figure 2). No significant disease was present in either the right coronary artery or the abnormally arising left circum- *National School of Chest Diseases, Madrid, Spain. Currently on sabbatical with the Department of Cardiology, Texas Heart Institute, Houston, Texas **Fulbright Grant with the Department of Cardiology, Texas Heart Institute, Houston, Texas ***Staff Cardiologist, Texas Heart Institute, Houston, Texas Present address: Providence Hospital, Columbia, S.C Cardiovascular Diseases, Bulletin of the Texas Heart Institute, Vol. 1, No. 5, 1974

2 _I I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.. 2,...~~~~~~~~~~~~~~~~~~~~~~... flex coronary artery (Figure 2). At the present time, the patient is being managed medically. CASE 3-A 56-year-old male with typical angina during the preceding year was admitted to the hospital in January, His physical examination was unremarkable. Cardiac catheterization and selective coronary angiograms showed extensive coronary artery disease. In addition, the left circumflex artery originated from the right sinus of Valsalva and shared a common ostium on the aorta with that of the right coronary artery (Figure 3). The patient subsequently underwent triple bypass grafting. However, after two months the patient was readmitted with severe typical angina. Restudy at that time showed all three grafts to be occluded. The patient was managed thereafter with medical therapy. CASE 4-A 37-year-old woman had symptoms of a typical angina. Her electrocardiogram showed ST segment depression and inversion of the T waves in the inferior leads, and a Master's exercise test was positive. Right and left heart catheterizations, with selective coronary angiography, were performed in May of Hemodynamics were normal. The coronary ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I Fig. 1. Shown above is a selective injection of the right coronary artery,rca4) in the left anterior oblique (LAO) projection The RCA is dominant The origin of the left circumflex (LCx) is abnormal. It arises from a common ostium with the RCA from the right aortic sinus of Valsalva. Its subsequent distribution is that of a conventionally arising LCx. (Case 1) 401

3 arteries were normal except that the circumflex artery shared a common ostium with the right coronary artery from the right aortic sinus of Valsalva (Figure 4 B). The left anterior descending artery arose normally from the left aortic sinus of Valsalva (Figure 4 A). This patient also had clinical and laboratory evidence of thyroiditis but was otherwise unremarkable. DISCUSSION The congenital malformations of the coronary arteries were divided by Edwards in and Ogden in as follows: A. Primary minor variations 1. Ostium of a coronary artery located superior to its usual level 2. Multiple ostia on a single sinus of Valsalva with at least one ostium on the opposite sinus of Valsalva 3. Variable origin of the left circumflex coronary artery 4. Variable origin of the left anterior descending coronary artery 5. Single coronary artery 6. Absence of any ostium of the proximal segment of any coronary... Fig. 2. Depicted above is the normal RCA of the patient presented as Case 2. The RCA is dominant with normal 'distrihution. The abnormal origin of the LCx is evident. 4.02

4 rme, A...-'.-M M L-4 "I'M0.E... Fig. 3. Pictured is the abnormal origin of the LCx shared with the RCA on the right aortic sinus of Valsalva. The LCx has a significant stenosis in the proximal segment. The RCA is occluded near its origin. The distal segment is partially opacified by collateral channels. (Case 3) A. _ -f::..~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.4-44 Fig. 4 A. The photograph is of a selective left coronary artery (LCA) injection in the posteroanterior (PA) projection. There is apparent absence of the LCx. (Case 4) 403

5 1. ~ artery on one sinus of Valsalva, but with presence of multiple ostia on the opposite aortic sinus 7. Intramural coronary artery B. Primary major anomalies 1. Coronary fistula a) with left-to-right shunt b) with left-to-left shunt 2. Abnormal origin from the pulmonary artery a) left coronary artery b) right coronary artery c) both coronary arteries d) accessory coronary artery C. Secondary anomalies 1. Secondary coronary fistula 2. Variations associated with other congenital malformations of the heart (Transposition of the great vessels, tetralogy of Fallot, single ventricle, etc.) Antopol and Kugel in were the first to describe the anomaly in which the left circumflex coronary artery arises from a common ostium... ~ ~ Fig, 4 B. The RCA injection in the sanie plane as that of Figure 4 A, howevei, shows thie typical distribution of the LCx, despite its abnormal origin fro-m the commnon ostium with tile RCA. 404

6 with the right coronary artery from the aorta on the right sinus of Valsalva. They originally described four cases, in one of which the circumflex was a branch of the proximal right coronary artery. In these four cases, the left circumflex artery followed its usual anatomical course. In the autopsy series of Alexander and Griffith,' four similar cases of the left circumflex coronary artery arising from the right sinus of Valsalva were described. The difference in these four cases was, however, that the ostium was entirely separate and not shared with the right coronary artery. In another four of their cases, the circumflex artery was a branch of the proximal right coronary artery, similar to the cases described by Antopol and Kugel in James,5 in his study of 106 hearts, found only one case of anomalous circumflex artery and that one was also a branch of the proximal right coronary artery. Lillehei6 reported on one case in which the right coronary artery gave rise to the circumflex artery. This discovery was associated with a mortality at the time of aortic valve replacement. The right coronary artery was selectively cannulated and the proximal origin of the left circumflex was completely occluded by the cannulating catheter. The patient died on the operating table, the assumption being that occlusion of the left circumflex coronary artery was the cause of death. Ogden et al. in 1970*3 reported on 14 cases of anomalous origin of the circumflex artery from the right coronary artery, and in a separate report Demany and Zimmerman presented a case in which a circumflex artery arose from the right coronary artery.7 The right coronary artery, however, arose separately from the right sinus of Valsalva. The left anterior descending branch of the left main coronary artery arose nearby from the left sinus of Valsalva. There has been a general division of opinion about whether the anomalous origins of the circumflex coronary artery from the right coronary artery represent primary anomalies or whether they are secondary anomalies more often associated with transposition of the great vessels. Although this paper does not specifically answer that point, in the four cases presented there was no evidence of other major cardiovascular anomaly. Notably, there was no cyanosis present, and there was no indication that major anatomical distortion of cardiac anatomy existed apart from the primary anomaly of the origin of the circumflex artery. Therefore, we think that the origin of the left circumflex artery from the right coronary artery is a primary anomaly in the development of the coronary vessels. Summarized in Table I are the different modalities of the anomalous origin of the circumflex artery from the right coronary artery (Types II, III, and IV) and also from an independent ostium located in the right aortic sinus of Valsalva (Type I). SUMMARY Four cases of anomalous origin of the circumflex artery from the right coronary artery are presented. With the inclusion of these cases, the world's literature, to our knowledge, contains descriptions of only thirty-two cases 405

7 of anomalous origin of the circumflex artery from the right coronary artery or the right sinus of Valsalva of the aorta. Of the twenty-eight previously described cases, only four are anatomically identical to the cases presented in this communication. In all four of these cases, the circumflex artery shares with the right coronary artery a common ostium on the right aortic sinus of Valsalva. The significance of this anomaly is perhaps threefold. The ostium is common to the right coronary artery and circumflex, making it less likely that the circumflex artery will be completely unidentified at the time of coronary angiography as might be the case, for example, in the Type I anomaly (Table I). On the other hand, a high-grade osteal lesion in this Type III anomaly would have the significance of two-vessel coronary artery disease, and would place the entire posterior circulation of the heart in jeopardy. A similar precarious situation also exists when a highgrade lesion occurs in the very proximal right coronary artery in the Type II form of anomalous origin of the circumflex (see Table I) or in the rare Type IV form. This is similar in significance to the situation in which there is a major narrowing of the left main coronary artery with normal origin of the left circumflex coronary artery. Finally, although in the above four cases exhaustive efforts were not made to exclude other minor congenital cardiovascular malformations, no other major anomalies were identified. It is concluded, therefore, that anomalous origin of the left TYPE I TYPE I TYPE Z TYPE V TABLE I > Antopol and Kugel (1932) 3 1 Alexander and Griff th (1956) 4 _ 4 Dadswell (1960) 1 James (1961) Lillehei (1964) l 1 Demany and Zimmerman (1967) 1 Ogden and Kabemba (1970) 3 1l Fuertes.Triveltato and Brooker(1974) 4 TOTAL The four anatomic variations of the origin of the left circumflex artery from the right coronary artery as described in the literature indicated. The Roman numeral designation is that of the authors. 406

8 circumflex coronary artery from a common ostium with the right coronary artery on the right sinus of Valsalva at the aorta can and does exist as a primary cardiovascular anomaly. REFERENCES 1. Alexander RW, Griffith GC: Anomalies of the coronary arteries and their clinical significance. Circulation 14:800, Edwards JE: Anomalous coronary arteries with special reference to arteriovenous-like communications. Circulation 17:1001, Ogden JA, Kabemba JM: Les variations des arteries coronaires. Revue de 224 cas. Acta Cardiol 25 suppl. 13:487, Antopol W, Kugel MA: Anomalous origin of the left circumflex coronary artery. Am Heart J 8:802, James TN: Anatomy of the Coronary Arteries. fpaul B. Hoeber, Inc., New York, N.Y., Lillehei CW, Bonnabeau Jr RC, Levy MJ: Surgical correction of aortic and mitral valve disease by total valve replacement. Geriatrics 240, April, Demany MA, Zimmerman HA: Congenital anomalies of the coronary arteries. Angiology 18:370, Fuertes A, Soto B, Calderon J, Barcia A: Coronariografia selectiva: tecnica y resultados. Revista Espanola de Cardiologia, December