Aims: Conventional echocardiographic (ECHO) parameters of left ventricular (LV) and right ventricular (RV) systolic and diastolic function have been shown to be load-dependent; however, the impact of preload reduction on tissue Doppler (TD) parameters of LV and RV function is incompletely understood. The aim of this study was to examine the effect of acute preload reduction by haemodialysis (HD) on conventional (ECHO) and TD imaging (TDI) indices of systolic and diastolic function of the left and right ventricles.
Methods and results: Seventeen chronically uremic patients (age 31 +/- 10 years), without overt heart disease underwent conventional 2D and Doppler ECHO together with measurement of longitudinal mitral and tricuspid annular motion velocities. Fluid volume removed by HD was 2706 +/- 1047 cm(3). Haemodialysis led to reduction in LV end-diastolic volume (P < 0.0001), end-systolic volume (P < 0.001), peak early (E wave) transmitral flow velocity (P = 0.0001), and the ratio of early to late Doppler velocities of diastolic mitral inflow (P = 0.021). For the LV, early diastolic (E0) TDI velocities and the ratio of early to late TDI diastolic velocities (E0/A0) only on the septal side of the mitral annulus decreased significantly after HD (P = 0.0001 and P = 0.009, respectively). In a subgroup of seven patients who sustained significantly larger fluid volume loses following HD, E0 and the ratio of E0/A0 at the lateral side of mitral annulus also decreased suggesting a greater resistance of the lateral annulus to preload changes. Systolic velocities decreased after HD on both sides of mitral annulus (septal 6.90 +/- 1.10 vs. 5.97 +/- 1.48 cm/s, P = 0.006; lateral 8.68 +/- 2.67 vs. 6.94 +/- 1.52 cm/s, P = 0.011). For the RV, systolic tricuspid annular velocities decreased (13.45 +/- 1.47 vs.11.73 +/- 1.90 cm/s, P = 0.002) together with early diastolic velocities after HD (13.95 +/- 2.90 vs.10.62 +/- 2.45 cm/s, P = 0.0001). Both systolic and early diastolic tricuspid annular velocities correlated directly with fluid removal (P < 0.01).
Conclusion: This study shows that both systolic and diastolic TDI velocities of the LV and RV are preload-dependent. However, the lateral mitral annulus is more resistant to preload changes than either the septal mitral annulus or the lateral tricuspid annulus.