Congenital absence of right coronary artery without any other associated anomalies
by Surender Malhotra, MD • Carolyn Landolfo, MD • Deepak Kapoor, MD
From Medical College of Georgia, Augusta, Georgia
INTRODUCTION
Anomalous coronary arteries are rare congenital cardiac defects with varying symptomatology and controversial clinical significance. These should be considered as a differential diagnosis, particularly when coronary schemia occurs in a child or young adult. The incidence of coronary anomalies in the general population has een estimated to be between 0.3% and 1.3%.1-2 One of the more serious anomalies involves the right coronary artery (RCA) originating from the left main (LM) coronary artery and coursing between the aorta and pulmonary artery,3-5 which may result in severe myocardial ischemia due to compression of the artery from the aorta and ulmonary artery.5-8 Congenital coronary anomalies are the second most common cause of sudden death in young athletes after hypertrophic cardiomyopathy.9,10 In this report, the authors describe a patient who had a single coronary artery with congential absence of RCA. Right coronary artery territory was supplied by the erminal portion of left circumflex coronary artery.
—Tasneem Z. Naqvi, MD, MRCP
Presentation
A 61-year-old female was referred to cardiology clinic for evaluation of atypical chest pain. She has history of chronic smoking, hypercholesterolemia, hypertension, and anxiety, and had been complaining of vague rightsided chest discomfort. Exercise Thallium perfusion scanning revealed a less than 10% reversible defect in the anteroapical region of the left anterior descending artery (LAD) territory. Due to her risk factors and a positive nuclear stress test, she was sent for cardiac catheterization.
Evaluation and diagnosis
Coronary angiography demonstrated a normal looking LM coronary artery giving rise to LAD and a large caliber left circumflex (LCx). The left anterior descending artery was normal and the LCx showed mild luminal irregularities. The distal LCx continued beyond the atrioventricular groove into right coronary artery territory to terminate close to base of the heart. We were unable to find the ostium of the RCA using a Judkins RCA 4.0 catheter. Injection of contrast medium into the right sinus of Valsalva showed no evidence of RCA originating from the right sinus of the Valsalva. There was no significant stenosis in any of the coronary arteries (Figures 1-3).
 |
| Figure 1. Coronary angiogram of left coronary tree showing continuation of distal left circumflex artery in right coronary artery territory. |
Discussion
Coronary anomalies are relatively common, with a reported incidence of 0.2% to 1.3% in the general population. 1,2,11 Most anomalies are clinically insignificant; however, some anomalies have been associated with adverse outcomes like angina, dyspnea, syncope, acute myocardial infarction, and even sudden death. Clinicians face the challenge of precisely identifying these anomalies associated with adverse outcomes. In this context, recognition of an anomalous origin of the coronary artery from the opposite sinus is particularly relevant due to the significantly increased mortality rate for an anomalous left coronary artery arising from the right sinus (57%) and RCA arising from the left sinus (25%).12
Single coronary arteries are very rare, with an autopsy incidence of 0.29%.2 Forty percent of the anomalies occur in association with other congenital cardiac abnormalities.3 An RCA originating from the LM coronary artery accounts for only 0.65% of these anomalies.1 Congenital absence of RCA has been described previously in a 38-year-old female with nonobstructive hypertrophic cardiomyopathy where RCA arose as an extension of terminal portion of LCx13 and in another 78-year-old female with obstructive hypertrophic cardiomyopathy where RCA arose as an extension of terminal portion of LAD.14 McMahon at al15 reported atresia of the proximal RCA in a 2-year-old boy that was associated with fistula from LAD to mid portion of the RCA. Our case represents first reported congenital absence of RCA without associated structural cardiac abnormalities.
 |
| Figure 2. Aortogram showing absence of origin of right coronary artery. |
Right coronary artery anomalies are of controversial significance. Virmani and associates found that in 21 patients with this anomaly, 10 died of cardiac causes, of which 5 were sudden (eg, 4 with no signs of atherosclerosis).16 There are 2 mechanisms of ischemia that have been proposed for these anomalies. The great vessels, which dilate during exercise, may externally compress the coronary artery.5-6 The second proposed mechanism suggests that valve-like ridges and the acute angulation of the artery as it traverses from the left to the right sinus may induce ischemia.6
In this case of absent RCA, the dominant LCx supplied the RCA territory. Since the left coronary artery assumed abnormal course, there was no concern for abnormal external compression causing ischemia. Due to the absence of coronary obstruction, the 10% anteroapical defect noted on perfusion imaging was attributed to a false positive test. Patient was reassured and advised for risk factor modification.
 |
| Figure 3. Coronary angiogram showing distal left circumflex artery in right coronary artery territory. |
In conclusion, congenital absence of RCA is a rare finding. At the current time, diagnosis of congenital coronary anomalies is made by coronary angiography. In the future noninvasive modalities including electrocardiographic-gated multidetector computed tomography (MDCT)7 and magnetic resonance imaging can also be used to make a definitive diagnosis.
References
- Yamanaka O, Hobbs RE. Coronary artery anomalies in 126 595 patients undergoing coronary arteriography. Cathet Cardiovasc Diagn. 1990;21:28-40.
- Alexander RW, Griffith GC. Anomalies of the coronary arteries and their clinical significance. Circulation. 956;14:800-805.
- Henson KD, Geiser EA, Billett J, et al. Use of transesophageal echocardiography to visualize an anomalous right coronary artery arising from the left main coronary artery (single coronary artery). Clin Cardiol. 992;15:462-465.
- Husaini SN, Beaver WL, Wilson IJ, et al. Anomalous right coronary artery arising from left mainstem. Cathet Cardiovasc Diagn. 1983;9:407-409.
- Bloomfield P, Erhlich C, Folland ED, et al. Anomalous right coronary artery: a surgically correctable cause of angina pectoris. Am J Cardiol. 1983;51:1235-1237.
- Lopushinsky SR, Mullen JC, Bentley MJ. Anomalous right coronary artery originating from the left main coronary artery. Ann Thorac Surg. 2001;71(1):357-358.
- Ghersin E, Litmanovich D, Ofer A, et al. Anomalous origin of right coronary artery: diagnosis and dynamic evaluation with multidetector computed tomography. J Comput Assist Tomogr. 2004;28(2):293-294.
- Iyisoy A, Kursaklioglu H, Barcin C, et al. Single coronary artery with anomalous origin of the right coronary artery as a branch from the left anterior descending artery: a very rare coronary anomaly. Heart Vessels. 2002;16(4):161-163.
- Basso C, Maron BJ, Corrado D, Thiene G. Clinical profile of congenital coronary artery anomalies with origin from the wrong aortic sinus leading to sudden death in young competitive athletes. J Am Coll Cardiol. 2000;35: 1493–1501.
- Maron BJ, Thompson PD, Ackerman MJ, et al for the American Heart Association Council on Nutrition, Physical Activity, and Metabolism. Recommendations and considerations related to preparticipation screening for cardiovascular abnormalities in competitive athletes: 2007 update: a scientific statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism: endorsed by the American College of Cardiology Foundation. Circulation. 2007;115(12):1643-1645.
- Mixon TA, Watson LE. Single coronary artery with an ectopic origin and interarterial course: a case report and review of the literature. Rev Cardiovasc Med. 2002;3:107-110.
- Angelini P. Coronary artery anomalies—current clinical issues: definitions, classification, incidence, clinical relevance, and treatment guidelines. Tex Heart Inst J. 2002;29:271-278.
- Atmaca Y, Dandachi R, Oral D. A rare variant of single coronary artery and nonobstructive hypertrophic cardiomyopathy. J Invasive Cardiol. 2002;14(8):469-470.
- Kursaklioglu H, Iyisoy A, Celik T, et al. An unusual type of single coronary artery anomaly in a patient with hypertrophic obstructive cardiomyopathy. Anadolu Kardiyol Derg. 2005;5(3):232-233.
- McMahon CJ, El Said HG, Clapp SK. Atresia of the proximal right coronary artery in association with coronary artery fistula. Catheter Cardiovasc Interv. 2000; 50(3):337-339.
- Virmani R, Rogan K, Cheitlin MD. Congenital coronary artery anomalies: pathologic aspects. In: Virmani R, Forman MB, eds. Nonatherosclerotic Ischemic Heart Disease. New York: Raven Press; 1989:172-173.
Related Articles - Images in Cardiology
|
|
Search
Resources
