In 38 patients with "pure" aortic stenosis, P terminal force in V(1)(V(1)Ptf) correlated well with left ventricular end-diastolic pressure (LVEDP) (n = 38, r =-0.59, p smaller than 0.001), Poorer, but nevertheless significant correlations were observed with aortic systolic pressure gradient (r = -0;32, p smaller than 0,05) and cardiac volume measured by X-ray (r = -0.34, p smaller than 0.05). No significant correlation was found between V(1)Ptf and peak systolic left ventricular pressure. If V(1)Pft more negative than -0.03 mm sec is used to detect elevated LVEDP (above 12 mm Hg), the sensitivity is 81 percent, and the specificity 86 percent. Increased left atrial volume is probably the most important mechanism of this relationship. V(1)Ptf is a useful tool for the assessment of the functional and hemodynamic state of the left ventircle in aortic stenosis.