Research On Hemodynamic Change Of Cardia Insufficiency Patient By Reconstructed Impedance Cardiogram

Objective To explore cardiac function change in the cardia insufficiency patients' by Reconstructed Impedance Cardiogram.Methods 1. ventricular premature beat was induced by cardiac catheter which was placed in anesthetic adult Dogs' endocardium of left ventricle, we tested the thoracic impedance changes of dogs at same time with 6 leads, getting the reconstructed impedance differential cardiogram by wave reconstructed, and then measured C wave amplitudes of AO,PL and PR differential components before premature beat and during premature, and then the relationship between changes of the AO component of the reconstructed impedance differential cardiogram and the volume change of aorta was analyzed. 2. Reconstructed impedance differential cardiogram was performed in two adults groups ( patient group ,control group) and the cardiac function was calculated by reconstructed impedance cardiographic non-linear formula. Separately using following parameter stroke volue(SV), cardiac output (CO),cardiac index (CI),cardiac work index(CWI),left ventricular ejection fraction(LVEF),left heather index(LHI),total peripheral resistance(TPR),aortic compliance(AC),left ventricle diastolic index(LDI),left ventricular end-diastolic pressure(LVEDP). 3. The correlation of left ventricle ejection fraction ( LVEF ) measured by reconstructed impedance cardiography(RICG) and by ultrasonic echocardiography(UCG)in 31 hospitalized patients was investigated, LVEF was separately measured with RICG and UCG within 4 hours.Results 1. As compared to the normal amplitudes before premature beat, the C wave amplitudes of AO decreased 80.4±20.0%during premature beat,that of PL decreased 25.4±21.4%,that of PR decreased 21.8±29.6%.Those indicated that influence of aortic volume change to the AO component should be much bigger than that to the PL and PR components , P <0.001. 2. LVEDP from patient group is obviously higher than that from control's as well as TPR and LDI while the others (SV,CO, CI, CWI, LVEF,LHI,AC) from patient group is lower than thosefrom control's (P< 0.05). 3 RICG′s LVEF was (59.0±9.0)% , UCG′s LVEF was (59.7±8.1)%,there are almost no difference between average values of two methods(P>0.05), then the coefficient of correlation r = 0.83(P<0.001)and the regression equation was Y = 0.75X + 15.5(P<0.001).Conclusions The AO component of the reconstructed impedance cardiogram may indirectly reflect the volume change of aorta. Reconstructed Impedance cardiography gives accurate and reproducible measurement of hemodynamics as doppler echocardiography .when applied in cardia insufficiency patient, it can provides reliable, easily, economic, safely, almost immediate acquisition of hemodynamic values.