The delayed upstroke of the arterial pulse in valvular aortic stenosis has been attributed, in part, to prolonged left ventricular emptying. Left ventricular emptying rate, however, has not been measured in aortic stenosis. We assessed the rate of left ventricular emptying by computer analysis of biplane cineangiograms in seven normal subjects, six patients with mild to moderate aortic stenosis, and 12 patients with severe aortic stenosis. As an indicator of delayed arterial pulse rise, T time index (time to half maximum aortic pressure corrected for heart rate) was measured in each group. T time index averaged 0.07 +/- 0.01 units in normal subjects, 0.14 +/- 0.04 units in the patients with mild to moderate aortic stenosis, and 0.13 +/- 0.05 units in those with severe aortic stenosis. Patients with mild to moderate and severe aortic stenosis differed significantly from normal subjects. Relative emptying rates were defined as the percentage of initial systolic volume ejected divided by the percentage of systole elapsed. These relative emptying rates were determined during the first, second, and third thirds of systole in all three groups. No significant decrease in the relative rate of left ventricular emptying was noted when each group of patients with aortic stenosis was compared with the normal subjects. Neither was there slowing in the actual rate of ejection of blood in ml per second throughout systole. We conclude that the rate of ventricular emptying is normal in aortic stenosis and does not explain the arterial pulse delay in this disease.