心阻抗图测定左室收缩功能IC指数的临床研究

Clinical Study of IC Index Estimation by the Thoracicelectrical Bioimpedance for Measuring Left Ventricular Contractility

目的研究左室收缩功能IC指数的临床意义。方法对31名心阻抗图异常A波者进行回顾分析由心阻抗图测定左室心肌收缩功能指数（indexofcontratility，IC）与同时测算的其它反映左室功能的指标间作相关分析。结果获得的IC指数与（dZ／dt）max、HI、SV／LVET、CI和EF高度相关，并且与PEP／LVET、A／C、A（dz／dt）max呈良好相关（P＜0.001）。但IC指数与Zo（基础阻抗）、HR、Q－Z等指标间无相关性。结论提示IC指数是一项不受HR、Zo影响且能反映左室心肌收缩强度的实用生理指标。A波异常、IC指标异常可能是充盈左房负荷加重，心肌收缩性差的表现。

0bjective and Methods In this study, the data analysis was performed inthirty - one retrospective cases that had an abnormal A wave form the impedancecardiography. Rcsults A linear regression analysis was used to compare the IC index valuswith simultaneous other pafamter such as (dz/dt)max, HI, SV/LVET, CI, EF. The correlationcoefficient showed an excellent correlation r=0.94, r=0.9O, r=0.77, r=0.57 respectively(P<0.001) and also c0nnected PEP/LVET, A/C, A(dz/dt)max but the correllation respectivelydid not significant1y change(P>0.O5) between IC index and Z0. HR and Q- Z werefound. Conclusion These preliminary observations suggest that the IC index by impedancecardiography might be a clinical useful tool for the detection of myocardial contractile forcewhich was not effect on the basic impedance (Zo) or on the heart rate (HR). The casescombined height of A wave and abnormal IC index might re f1ect the load elevated for fillyleft atrial and a poor efficiency of myocardial contractile force.