Anomalous Origin and Course of the Right Coronary Artery
Coronary anomalous origin from the wrong aortic sinus has been thought to be a risk factor for ischemia because of acute takeoff from the aorta and flow between the aorta and the pulmonary artery.1–4 A 30-year-old man suddenly died within an hour of waking. His clinical history revealed no evidence of any disease, and the postmortem toxicological examination was negative. Autopsy ruled out violent or natural noncardiac causes of death and revealed an underlying congenital heart disease, which was characterized by a congenital bicuspid aortic valve and an anomalous origin of the right coronary artery just above the median raphe of the anterior cusp (Figure 1).
The proximal segment of the right coronary vessel showed a flutebeak-shaped ostium that was partially covered by a semilunar valvelike fold of the aortic wall and a left-to-right acute-angle course with slit-like lumen between the aorta and the pulmonary artery (Figure 1). Both the left circumflex and the interventricular coronary arteries originated directly from the tubular portion of the ascending aorta through 2 separated ostia, and both were patent (Figure 2).
Histopathologic examination of the heart showed multiple acute and chronic ischemic lesions, which were mostly localized in the myocardium supplied by the anomalous dominant right coronary artery. Ischemic lesions included coagulative myocytolysis and substitutive fibrosis (Figure 3).
The findings reported above suggest an arrhythmic sudden cardiac death triggered by myocardial ischemia due to right coronary artery obstruction caused by its anomalous origin and course.