To assess the clinical significance of coronary artery ectasia 4993 consecutive coronary arteriograms were reviewed to identify patients with this condition and to allow the assessment of their progress. Coronary ectasia was a relatively uncommon finding (overall incidence 1-4%). It was not related to the development of aortic aneurysms and did not affect the outcome, results of coronary artery surgery, or symptoms. Coronary artery ectasia has been a well recognised, if uncommon, pathological finding for many years.' The advent of cardiac catheterisation allowed the di- agnosis to be made in life, and associations have been reported with trauma,2 polyarteritis nodosa,3 Tak- ayasu's disease,4 mucocutaneous lymph node syn- drome,5 congenital abnormalities,6 and syphilis. In westem populations the most common association is with atherosclerotic coronary artery disease. Esti- mates of the incidence of coronary ectasia have var- ied from 0 3%7 to 4-7%.8 As definitions of ectasia in the...