Single coronary artery with branching of the right coronary artery from the left atrioventricular ramus of the circumflex artery. Incidence and significance

In a series of 8500 consecutive coronary angiographies, we found three times an "anatomic single coronary artery" with origin of the right coronary artery from the AV-branch of the dominant circumflex artery (incidence 0.035%). In all three patients the investigation was made because of the suspicion of coronary heart disease. All 59 previously published cases (44 found at coronary angiography, 15 at necropsy) and our own three cases were not associated with other cardiovascular anomalies. A pathophysiological significance of this anomaly alone with regard to inducing myocardial ischemia can almost be excluded. The knowledge of this anomaly however is important to avoid errors in diagnosis and to evaluate the exact degree of severity of coronary heart disease.