Steendijk P, Van der Velde E T, Baan J
Department of Cardiology, Leiden University Hospital, The Netherlands.
Am J Physiol. 1993 Jun;264(6 Pt 2):H2198-207. doi: 10.1152/ajpheart.1993.264.6.H2198.
The conductance method employs a multielectrode catheter to measure intracavitary electric conductance from which left ventricular volume is estimated. A dual-excitation method introduced by us uses a more homogeneous electric field and thereby should enable more accurate volume estimation. In six anesthetized open-chest dogs we compared stroke volume obtained from electromagnetic flow probes with the conventional single-excitation method and with the new dual-excitation conductance method. Caval occlusion and left atrial hemorrhage were used to obtain a wide range of stroke volumes. The slope of the relation between stroke volume calculated from the flow probes and from the conductance catheter increased significantly (P < 0.001) from 0.635 with single excitation to 0.835 with dual excitation, but the interanimal variability was not reduced. The linearity of the relation was substantially improved.
电导法采用多电极导管来测量心腔内的电导，据此估算左心室容积。我们引入的双激励法使用了更均匀的电场，因此应该能够实现更精确的容积估算。在6只麻醉开胸犬中，我们将通过电磁流量探头获得的每搏输出量与传统单激励法及新的双激励电导法进行了比较。采用腔静脉闭塞和左心房出血的方法来获得范围广泛的每搏输出量。根据流量探头和电导导管计算出的每搏输出量之间关系的斜率，从单激励时的0.635显著增加（P<0.001）至双激励时的0.835，但动物间的变异性并未降低。该关系的线性得到了显著改善。
