Abe S, Ohtomo J, Yamaguchi I, Tsuchida E, Fujinuma T, Sunagawa K, Tomoike H
First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Heart Vessels. 1995;10(3):138-45. doi: 10.1007/BF01744480.
We developed a device for monitoring instantaneous left ventricular (LV) volume using an alternating-current excitation two-electrode conductance catheter. Instantaneous conductance between a pair of electrodes was amplified by a non-inverting circuit. The level of conductance was linearly related to changes in blood volume from 0.8 to 2.0 ml in a latex balloon (r2 = 0.95), and to changes in blood volume from 0.4 to 2.2 ml in a post-mortem rabbit left ventricle (r2 = 0.99). The difference between the maximal and minimal conductance of the LV in situ during a cardiac cycle was closely correlated with changes in stroke volume, measured by an electromagnetic flow probe (r2 = 0.97). The endsystolic pressure-conductance relation (ESPCR) was highly linear (r2 = 0.92). Changes of the slope (Ees) of the ESPCR correlated directionally with changes of the time derivative of LV pressure (LVdP/dt) during intravenous infusions of dobutamine and propranolol. Accordingly, the two-electrode conductance catheter was useful in vivo in rabbits for continuously assessing changes in the LV volume.
我们开发了一种使用交流激励双电极电导导管监测左心室（LV）瞬时容积的装置。一对电极之间的瞬时电导由一个同相电路放大。在乳胶气球中，电导水平与0.8至2.0毫升血容量的变化呈线性相关（r2 = 0.95），在死后兔左心室中与0.4至2.2毫升血容量的变化呈线性相关（r2 = 0.99）。心动周期中左心室原位最大和最小电导之间的差异与电磁流量探头测量的每搏输出量变化密切相关（r2 = 0.97）。收缩末期压力-电导关系（ESPCR）呈高度线性（r2 = 0.92）。在静脉输注多巴酚丁胺和普萘洛尔期间，ESPCR斜率（Ees）的变化与左心室压力的时间导数（LVdP/dt）的变化呈方向相关。因此，双电极电导导管在兔体内可用于连续评估左心室容积的变化。
