诱发室性早搏对重建心阻抗图AO分量影响的实验研究

An Experiment Research on Influence of Induced Ventricular Premature Beats to the AO Component of Reconstructed Impedance Cardiogram

目的探讨重建心阻抗图AO分量的阻抗变化与主动脉容积变化的关系。方法用心导管刺激狗的左室后壁心内膜,诱发室性早搏,改变射入主动脉的血量,用六导联同步检测狗的胸部体表阻抗变化,通过波形重建得到狗的重建心阻抗微分图,分别测量正常时、早搏时对应的AO、PL和PR分量的C波幅度。结果与早搏前正常的C波幅度相比,早搏时AO分量的C波幅度下降(80.4±20.0)%,PL分量下降(25.4±21.4)%,PR分量下降(21.8±29.6)%;这表明主动脉容积变化对AO分量的影响比对PL、PR分量的影响大得多(P<0.001)。结论重建心阻抗图AO分量的阻抗变化能够间接地反映主动脉的容积变化。

Objective To investigate the relation between the AO component＇s impedance change of the reconstructed impedance cardiogram and the volume change of aorta. Methods The left ventricle posterior wall of dog with cardiac catheter was excited to induce ventricular premature beats and to change blood volume electing in aorta,the thoracic impedance changes of dog at same time with 6 leads were tested, the reconstructed impedance cardiogram was get by wave reconstruction,the C wave amplitudes of AO,PL and PR differential components before premature beat and during premature beat were measured, and the decreased amplitudes and corresponding percenta- ges were calculated. Results As compared with the normal amplitudes before premature beat, during premature beat the C wave amplitude of AO decreased（80. 4 ± 20. 0）%, that of PL decreased （25.4 ± 21.4） %, that of PR decreased （21.8 ± 29. 6） %. Those indicate that influence of aortic volume change to the AO component is much bigger than influence to the PL and PR components（P〈0. 001）. Conclusion The AO component of the reconstructed impedance cardiogram may indirectly reflect the volume change of aorta.