Quantitative two-dimensional (2-D) and Doppler echocardiography were used to determine whether hemodialysis results in alterations in left ventricular (LV) diastolic filling that might contribute to dialysis-induced hypotension, as well as to assess whether any hemodynamic variables or indices of diastolic filling might be used to identify which patients were at the greatest risk of becoming hemodynamically unstable during dialysis. Sixteen male patients undergoing routine maintenance hemodialysis for end-stage renal disease were prospectively studied before and after hemodialysis. Following hemodialysis there was a significant prolongation (P less than 0.05) in LV isovolumetric relaxation time (IVRT), as well as a significant reduction in the rate and extent of early rapid ventricular filling (P less than 0.005); in contrast, late atrial-assisted filling did not change significantly. A multiple stepwise linear regression analysis of predialysis hemodynamic parameters and noninvasive indices of LV filling showed that there was a significant independent inverse relationship between the frequency of dialysis-related hypotensive episodes and the duration of early LV filling (r = -0.81; P less than 0.001). These results suggest that hemodialysis results in discrete alterations in early LV filling, with no significant compensatory increase in late atrial-assisted ventricular filling. Further, patients with the shortest early LV filling times appeared to have the greatest predilection for becoming hemodynamically unstable during dialysis.