Abstract
We report an interesting case of single right coronary artery arising from the right sinus of Valsalva and continuing distally as a rare anomalous left coronary artery. Over the 7-year course of our clinical follow-up, the right coronary artery manifested severe, progressive atherosclerotic disease in multiple sites, which lesions were successfully stented. We hypothesize that the disease process in the right coronary artery was accelerated by shear stress in association with that vessel's need to carry the entire burden of the coronary circulation.
Key words: Atherosclerosis, coronary; coronary vessel anomalies/diagnosis/pathology/classification; heart defects, congenital/diagnosis/pathology/classification; stents
We describe a case of single dominant right coronary artery (RCA) arising from the right sinus of Valsalva, in which the RCA continued distally as a rare anomalous left coronary artery and supplied the entire myocardium. We believe this to be an extremely rare variant of a single right coronary artery. Over the course of 7 years of clinical follow-up, our patient developed, sequentially, severe multiple RCA atherosclerotic lesions, and these were treated successfully with multiple stent angioplasties.
Case Report
In 2003, coronary angiography was performed in a 66-year-old man who had presented with angina and atrial fibrillation. He had a history of smoking and a family history of coronary artery disease. The angiogram revealed absence of the left coronary ostium. The patient's entire left circulatory system filled via the RCA, which coursed down the right atrioventricular groove normally, giving off posterolateral and posterior descending artery (PDA) branches. The PDA continued around the apex as the left anterior descending coronary artery, which terminally branched into a small patent left circumflex coronary artery and ramus intermedius artery (Fig. 1). There was no left main coronary artery. A computed tomographic angiogram (Fig. 2) also confirmed the anomaly. Although disease in the distal RCA and proximal PDA was at that time noncritical, angiography repeated a year later for acute coronary syndrome showed significant disease progression: an ulcerated 80% lesion in the mid-RCA, a 70% lesion in the distal vessel before the PDA, and a 60% to 70% lesion in the PDA itself. The patient was treated with balloon angioplasty and stenting. In 2007, a coronary angiogram—repeated after a recurrence of acute coronary syndrome—showed a fresh lesion in the posterolateral branch of the RCA that also needed stenting. In March 2010, after recurrence of angina, a repeat angiogram showed patent stents and noncritical lesions in the RCA (Fig. 3).
Fig. 1 Initial angiogram shows a single right coronary artery that continues distally as a left anterior descending coronary artery, then branches terminally into a left circumflex coronary artery and ramus intermedius. At this time, the disease in the right coronary artery was noncritical.
Fig. 2 Computed tomographic angiogram (multiplanar reformatted image) shows a single right coronary artery (RCA) and an absent left main stem.
Fig. 3 Angiogram after percutaneous coronary intervention shows patent stenotic segments.
Discussion
In left main coronary artery atresia, there is no left coronary ostium: the proximal left main trunk ends blindly, and blood flows from the RCA to the left coronary artery via small vessels and retrograde in at least one of the left-sided arteries.1 The differentiating feature of our case is the absence of a left main trunk. A single coronary artery in which the left coronary artery circulation arises from the distal continuation of a dominant RCA is an extremely rare anomaly.2,3 Percutaneous transluminal coronary angioplasty and stenting in a single coronary artery have occurred,4 although not in serial fashion as in our patient. We hypothesize that the RCA, which carried the entire burden of the coronary circulation, was exposed to more shear stress and therefore to acceleration of disease.
Footnotes
Address for reprints: Pradeepto Ghosh, MRCP, 38-6 Revere Road, Drexel Hill, PA 19026
E-mail: pradeeptoghosh@yahoo.com
References
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