Latent coronary heart disease was suspected in 115 of 2014 apparently healthy middleaged men after a baseline cardiovascular survey. One hundred five of these men underwent angiography and 36 were found to have normal coronary arteries (group 1). A 7 year follow-up survey revealed that: (1) three had died of sudden cardiac death, (2) four had received a diagnosis of cardiomyopathy, (3) one had developed aortic dilatation/aortic regurgitation since the baseline survey, (4) they all had a significantly more rapid decline in their physical performance and maximal heart rate levels from the time of the baseline survey to follow-up than did randomly selected normal controls (group 2), and (5) thallium study results were normal in both groups (27 and 26 patients), but technetium ventriculography revealed a subnormal increase in ejection fraction during exercise (< 5% units) in 14 of 27 group 1 subjects and in 4 of 26 group 2 subjects. Thus, incipient heart disease may be present in subjects in whom coronary angiographic examination has removed a previous suspicion of coronary heart disease.Circulation 68, No. 3, 490-497, 1983. EXERCISE ELECTROCARDIOGRAPHIC (ECG) testing is valuable in the evaluation of patients with chest pain and as a screening procedure in apparently healthy subjects. For the purpose of this study, performed 6 to 9 years after the one described above, the "angionegatives" were assigned to group I, and the men participating as control subjects (group 2) were selected as follows. Each time one of the men from group I was examined, the next man to be examined was designated a normal control subject, provided he belonged to the normal CIRCULATION