Rapid left-ventricular (LV) diastolic filling assessed by radionuclide ventriculography is reevaluated in patients with coronary artery disease and normal LV systolic function considering the effects of age and heart rate. Thirty normal subjects were studied along with 44 patients with coronary artery disease and normal LV ejection fractions. The peak filling rate was not quite significantly different between the controls and patients (2.67 +/- 0.95 EDV/sec versus 2.25 +/- 0.65 EDV/sec, p = 0.08), and the time to peak filling rate was not different. When an inappropriate young control group was compared with coronary disease patients aged 40-65 yr, large differences in peak filling rate were seen. Sensitivity for detection of disease was very low (0%-9%) except when the inappropriate young control group was used. Thus, analysis of rapid diastolic filling cannot detect individual patients with coronary disease who have normal LV ejection fractions. Previous reports to the contrary may have suffered from failure to include the effects of age and heart rate.