Single coronary artery arising from the right coronary sinus. Two cases reports

The authors report two cases of single coronary artery arising from the rig ht coronary sinus. Both patients had angina with reversible myocardial isch aemia on exercise Thallium scintigraphy. Coronary angiography showed single coronary artery arising from the right coronary sinus in both cases with s evere stenosis of the right coronary artery in the first and occlusion of t he right coronary artery in the second patient. Both underwent surgical revascularisation with a good result. Single corona ry artery is a rare congenital abnormality (approximately 0.36 per 1 000) d iagnosed at autopsy until 1963, and thereafter at coronary angiography. A r eview of the literature shows that an equal number of single coronary arter ies arise from the right as from the left coronary sinus : there does not s eem to be an increased risk of complication when a branch runs between the aorta and pulmonary artery. On the other hand, single coronary arteries ari sing from the right coronary sinus seem to be more commonly associated with atherosclerosis than a network with two coronary arteries, but when the le sions are proximal, the risk is high. Revascularisation is indicated only w hen myocardial ischaemia has been documented.