|Year : 2018 | Volume
| Issue : 1 | Page : 22-24
Congenital absence of left circumflex coronary artery and stenting of the stenosed proximal left anterior descending artery in a young male
Meenakshi Kadiyala, Cecily Mary Majella, S Vijaysekaran, S Suresh Kumar, Sundar Chidambaram
Department of Cardiology, Rajiv Gandhi Government General Hospital, Chennai, Tamil Nadu, India
|Date of Web Publication||27-Apr-2018|
Rajiv Gandhi Government General Hospital, Chennai, Tamil Nadu
Source of Support: None, Conflict of Interest: None
Congenital absence of the left circumflex artery is a rare anomaly of the coronary circulation with a prevalence ranging from 0.6% to 1.3%. We report a 33-year-old male who presented with recent anterior wall myocardial infarction, in whom coronary angiography revealed absent left circumflex artery and stenosed left anterior descending artery. The left circumflex territory was being perfused by the superdominant right coronary artery. Although the absence of an artery is mostly considered as a benign condition, atherosclerotic lesions may diminish the compensatory mechanisms and worsen the outcome.
Keywords: Circumflex artery, congenital absence, coronary anomaly
|How to cite this article:|
Kadiyala M, Majella CM, Vijaysekaran S, Kumar S S, Chidambaram S. Congenital absence of left circumflex coronary artery and stenting of the stenosed proximal left anterior descending artery in a young male. Heart India 2018;6:22-4
|How to cite this URL:|
Kadiyala M, Majella CM, Vijaysekaran S, Kumar S S, Chidambaram S. Congenital absence of left circumflex coronary artery and stenting of the stenosed proximal left anterior descending artery in a young male. Heart India [serial online] 2018 [cited 2020 Jul 15];6:22-4. Available from: http://www.heartindia.net/text.asp?2018/6/1/22/231345
| Introduction|| |
Congenital coronary artery anomalies, not infrequently seen during coronary angiography, have a prevalence ranging from 0.6% to 1.3%. Of these, 80% are benign and asymptomatic and 20% are clinically important. Congenital absence of the left circumflex coronary artery (LCX) is an extremely rare vascular anomaly, in which the artery fails to develop in the left atrioventricular groove. The prevalence of this anomaly is about 0.003%. In literature, absent LCX has been an associated with systolic click syndrome. Ischemic changes  can occur in the zone of hypoperfusion and may sometimes lead to dilated cardiomyopathy that can portend a poor prognosis. Here, we describe a case of absent LCX with myocardial infarction due to the occlusion of the proximal left anterior descending (LAD) artery.
| Case Report|| |
A 33-year-old male, nonhypertensive, nondiabetic, and chronic smoker presented with recent anterior wall myocardial infarction. Electrocardiogram showed evolved anterior wall myocardial infarction. Transthoracic echocardiography revealed regional wall motion abnormalities in the LAD territory with normal left ventricular dimension and ejection fraction of 46%. After optimal medical management, the patient was posted for coronary angiography using right femoral artery approach. The angiogram showed that only one artery arose from the left sinus of Valsalva and continued as the LAD. The proximal segment showed 70% stenosis with distal TIMI 1 flow [Figure 1]. No obvious LCX was demonstrated even after taking several different angiographic views [Figure 2] and [Figure 3]. Right coronary artery (RCA) originated normally from the right sinus of Valsalva [Figure 4]. It was a superdominant RCA which ascended the posterior atrioventricular groove beyond the crux. Aortic root angiogram also did not reveal any evidence of anomalous origin of the LCX [Figure 1]. Percutaneous coronary intervention (PCI) using 3 mm × 23 mm bare-metal stent was deployed across the proximal LAD lesion successfully after initial plain balloon dilatation post PCI angiography revealed distal TIMI III flow in LAD artery [Figure 5].
|Figure 1: Aortic root injection showing right coronary artery from the right sinus and left anterior descending from the left sinus|
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|Figure 5: Postpercutaneous transluminal coronary angioplasty to the left anterior descending|
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| Discussion|| |
Coronary artery anomalies are a group of diseases of varying hemodynamic consequences ranging from mild to life-threatening. These anomalies are generally discovered incidentally during coronary angiography. Separate origins of the LAD and LCX arteries from the left sinus of Valsalva are the most common of these anomalies with an incidence of 0.41%. It constituted 30.4% of all coronary anomalies in the series by Yamanaka and Hobbs, which is the largest study on that area in the literature. The absence of LCX is extremely rare, and lack of a coronary artery in the left atrioventricular groove confirms the diagnosis of absent LCX. Normally, the LCX and RCA run around the atrioventricular groove and form a circle; therefore, the absence of LCX is usually compensated with the large superdominant RCA, crossing the crux, and perfusing the LCX territories  as in our patient. Due to this anatomical compensatory mechanism, the condition is generally considered to have a benign outcome unless it is superimposed by atherosclerotic coronary artery disease.
Mievis has reported myocardial infarction in a 31-year-old male with absent LCX even with no obvious coronary artery narrowing. Likewise, severe stenosis of LAD may often lead to a fatal outcome even in the presence of a well-developed and superdominant RCA whose branches perfuse the LCX territory and also a zone of LAD. In cases with absent LCX, poorly developed RCA is considered as a subtype of coronary artery hypoplasia syndrome. True congenital absence of a coronary artery is expected to lead to hypoplasia of the dependent myocardium.
| Conclusion|| |
We report this case of congenital absence of the left circumflex coronary artery for its rarity, prompt recognition of the anomaly, and its association with atherosclerotic coronary artery disease of the proximal LAD which was managed by timely intervention. The keynote is that failure to visualize a coronary artery in its expected anatomic site should not be interpreted as a total occlusion. Aortic root angiography is mandatory in all cases where a coronary artery cannot be identified before it can be reported as occluded, absent, or having an anomalous origin or course.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]