Anomalous origin of left main coronary artery from the right sinus of Valsalva presenting as non ST elevation acute coronary syndrome: A case report.

Congenital anomalies of the coronary arteries are a cause of sudden cardiac death. Of the known anatomic variants, anomalous origination of a coronary artery from an opposite sinus of Valsalva (ACAOS) remains a major clinical issue and a challenging condition to treat. Congenital coronary anomalies are likely to be under-recognized, as completing an anatomic assessment in a very large portion of the population would seem unfeasible. However, we present a case report with image of a 49 year old male presented with acute non-ST elevation ACS for which he underwent diagnostic angiography of the coronary system which revealed a common origin of both right and left main coronary artery from right sinus of Valsalva with significant obstructive lesion in the mid segment of right coronary artery. However, due to financial constraints CT angiography could not be done in this patient to identify the detail anatomy and the course of the anomalous left coronary artery origin (L-ACAOS). He was managed medically with dual antiplatelets, beta blockers, nitrates and ACE inhibitors.

Case report

A 49 year old male, with no past co-morbidities presented with retrosternal chest pain of 2 day duration with increased severity few hours prior to admission. He was evaluated and ECG revealed ST depression in inferolateral leads with cardiac enzymes being positive. Other laboratory parameters included Hb% 13 g/dl, TLC – 7800/cumm, Platelets – 178,000/cumm, Na + 136 mEq/L, K + 4 Creatinine 0.8 mg/dl and urea 20 mmol/L. A diagnostic coronary angiography was done which revealed common origin of both the right main coronary artery and left main coronary artery arising from right sinus of Valsalva with obstructive disease in middle segment of right coronary artery. A detailed anatomic analysis of the coronary artery system and its course could not be defined due to financial constraints. He was medically managed and discharged with antiplatelets, beta-blockers and nitrates.

Discussion

Coronary artery anomalies represent a life-threatening form of congenital cardiac pathology. The underlying cause of sudden cardiac death in patients with congenital coronary abnormalities is multifactorial and has been stated with multiple competing theories. Death may result from contortion of the vessel’s slit-like, tangential origin during exercise leading to ischemia and resultant arrhythmia. Another theory purports that compression of the anomalous coronary occurs with dilation of the aorta and pulmonary artery during exercise. It is also possible that frequent episodes of myocardial ischemia lead to myocardial fibrosis and potential nidus for a deadly arrhythmia.1, 2

Anomalous origin of the left coronary artery from the right sinus of Valsalva may be further separated into four separate subtypes: (1) The left main coronary artery courses between the aorta and the pulmonary artery; (2) the left main coronary artery tracks anteriorly over the right ventricular outflow tract; (3) the left main coronary artery takes an intramyocardial course before resurfacing at the proximal portion of the interventricular groove; and (4) the left main coronary artery passes posteriorly around the aortic root. Of these, the first anomalous configuration is classically considered the most dangerous placing patients at the highest risk of sudden cardiac death.

In this report, we present a case with the classical angiographic finding with common origin of right and left main coronary arteries from the right sinus of Valsalva, i.e. Anomalous origin of left coronary origin from the opposite Sinus (L-ACAOS) (Figure 1, Figure 2, Figure 3). He presented with acute coronary syndrome (NSTE-ACS) for which he was managed medically and later detail anatomy and the arterial course could not be studied because of financial constraints. He was later discharged in a hemodynamically stable state on antiplatelets, statin, beta blocker and nitrates and asked for regular follow up. In literature, the angiographic study completed by Yamanaka and Hobbs found the overall incidence of coronary artery anomalies in a population of more than 120,000 patients to be ∼1.3%. with L-ACAOS found in only 22 patients comprising a fairly small portion of abnormalities which was considered potentially serious. Treatment of coronary artery anomalies is controversial and dependent on the discovered anatomy. Surgery is the mainstay of treatment, though beta-blockers and calcium channel blockers have been utilized to lessen ischemic symptoms. Angelini et al. opine that symptomatic patients should be treated with beta-blockers and should be advised to avoid strenuous physical exertion. Percutaneous or surgical treatment is reserved for anomalies with preaortic trajectories of the anomalous artery course.

Figure 1

LAO cranial view showing common origin of both RCA main coronary artery and Left main coronary artery.

Figure 2

LAO view to show same origin of both coronaries.

Figure 3

LAO view to show left coronary system arising from right sinus.