前负荷对组织多普勒成像技术评价左心室舒张功能的影响

目的探讨应用组织多普勒成像(TDI)技术评价心室舒张功能时是否受前负荷改变的影响。方法对30例血液透析的慢性肾功能不全患者,根据其透析前后体质量变化是否>2kg分为A组(<2kg)和B组(≥2kg),分别在透析前后用脉冲多普勒测量二尖瓣口及肺静脉血流频谱(E峰、A峰、S峰、D峰),并用TDI测量二尖瓣瓣环及各室壁中段的收缩期峰值速度(Sa和Sm)、舒张早期峰值速度(Ea和Em)及舒张晚期峰值速度(Aa和Am)。结果与透析前相比较,A组透析后Em减低(P<0.01),Em/Am降低(P<0.05),其余参数差异均无统计学意义;B组E峰、E/A、S峰及D峰降低(P<0.05),S/D值增加(P<0.05),Ea、Em、Ea/Aa及Em/Am均减低(P<0.01)。结论TDI在评价心室舒张功能时,与彩色多普勒血流显像一样受前负荷的影响,且与前负荷变化程度有关。

Effect of the preload on tissue Doppler imaging evaluating left ventricular diastolic function

Objective To assess whether the diastolic parameters measured by tissue Doppler imaging(TDI) are influenced by preload.Methods Thrity patients with chronic renal failure without overt heart disease receiving regular hemodialysis were divided into two groups:thirteen patients with the hemodialysis amount less than 2 kg(group A),seventeen patients with the hemodialysis amount more than 2 kg(group B).All these patients were studied by color pulsed-wave Doppler imaging(CPWDI) and TDI within one hour before and after hemodialysis.Transmitral diastolic velocities were recorded by CPWDI(E velocity and A velocity).TDI sample volume was placed at the mitral annular and midsegment of myocardial wall of the left ventricle.Peak systolic annular and myocardial velocity(Sa,Sm),peak early diastolic annular and myocardial velocity (Ea,Em),and peak late diastolic annular and myocardial velocity (Aa,Am) were measured.Results In group A,the changes of diastolic parameters showed insignificant chang except Em and Em/Am.In group B,the change of all parameters showed statistically significant differences except A,Aa,Am,Sa and Sm.Conclusions Diastolic parameters messured by TDI are affected by acute preload reduction,when the amount of change during hemodialysis is more than 2 kg.