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A 53-year-old man, positive for the human immunodeficiency virus and with hypertension and prior cocaine use, presented to his primary physician with progressive dyspnea on exertion and decreased exercise tolerance. He was referred for an exercise thallium stress test, during which he developed 2.5-mm ST-segment depressions in multiple leads. Perfusion imaging revealed a small, reversible apical defect. A left ventricular ejection fraction of 0.35 was calculated by use of gated single-photon-emission computed tomographic images. The patient was started on an aggressive medical regimen, and he was referred for transthoracic echocardiography (TTE) and selective coronary angiography in order to determine the degree and cause of his cardiomyopathy. The TTE revealed a mildly depressed left ventricular ejection fraction of 0.45, stage II/IV diastolic dysfunction, normal left ventricular geometry, and no regional wall-motion abnormalities.
The patient's coronary angiogram revealed an anomalous origin of the right coronary artery (RCA) from the left anterior descending artery (LAD), just distal to the takeoff of the 1st septal perforator (Figs. 1, ,2,2, and and3).3). The RCA then coursed anterior to the pulmonary artery and right ventricular outflow tract before it entered the right atrioventricular groove and assumed the course of a normal middle and distal RCA. In addition to this coronary anomaly, the patient's LAD and left circumflex coronary artery arose from separate ostia in the left sinus of Valsalva—an anomaly commonly referred to as “absent left main,” wherein the left main coronary artery is absent (most clearly illustrated in Fig. 1). Angiography of the right sinus of Valsalva revealed no coronary ostia. All vessels were free of angiographically significant stenoses.
This is the 1st report of an absent left main coronary artery in combination with an anomalous RCA originating from the middle LAD.
The prevalence of an anomalous origin of the RCA on coronary angiography has been reported as 0.27% in the largest series, which included 126,595 patients.1 Of these, the RCA originated from the left sinus of Valsalva (0.107%), the thoracic aorta (0.15%), the left main coronary artery (0.009%), the posterior sinus of Valsalva (0.003%), or the pulmonary artery (0.002%). Anomalous origin of the RCA from the LAD is exceedingly rare, with only 16 case reports having been published and the true prevalence of the anomaly unknown. All prior reports describe a single coronary artery, originating in the left sinus of Valsalva, with the takeoff of the RCA in proximity to the 1st septal perforator. Amasyali and colleagues2 described a highly unusual intraseptal course of the anomalous RCA. Canbay and associates3 used conventional angiography and computed tomographic angiography to show the more typical epicardial course, as seen in our patient.
Absent left main, in contrast, is a much more common finding on coronary angiography, with its prevalence estimated at 0.4% to 0.67%.1,4 Absent left main has been associated with a higher incidence of left-sided dominance, and with a low incidence of other congenital heart disease.4
The coronary anomalies that were seen on angiography were not believed to be the cause of our patient's clinical presentation. The exceedingly rare and interesting combination of these anomalies could warrant further research into their clinical significance.
Address for reprints: Andro G. Kacharava, MD, Atlanta VA Medical Center, 1670 Clairmont Rd., Room 2A171, Decatur, GA 30033. E-mail: ude.yrome@rahcaka