Stroke Volume and Mitral Annular Velocities: Insights from Uremic Patients with Significant Valvular Regurgitation

Abstract

This study investigates the change in new diastolic indices in uremic patients who undergo regular hemodialysis (H/D). We studied uremic patients receiving regular H/D. All patients were sinus rhythm before H/D. They had normal left ventricular systolic performance without regional wall motion abnormality. Patients were separated into two groups according to whether they had significant aortic or mitral regurgitation (AR or MR) or not. They received complete transthoracic echocardiographic examinations. Stroke volume (SV) was calculated as the product of the time-velocity integral (TVI) and cross-sectional area of aortic annulus. Flow propagation velocity (FPV) was measured by color M-mode echocardiography in apical four-chamber view. Mitral annulus tissue Doppler velocities--peak systolic (Sa), early diastolic, and late diastolic--were measured from septal and lateral wall. All these parameters were obtained immediately before and after H/D. Paired data were compared. H/D amount was strongly correlated with the change of SV. After H/D, the reduction of SV in patients without AR or MR (control group) was obvious but it was not significant in patients with significant AR or MR (study group). There were significant differences in mitral inflow velocities, FPV, and mitral annular velocities (except septal Sa) in the control group. In the study group, predialytic and postdialytic parameters of new diastolic indexes had no statistical difference. New echocardiographic indexes of uremic patients with significant AR or MR were relatively preload-independent. The phenomenon was possibly related to insignificant change of SV after H/D.