CONTINUOUS MEASUREMENT OF LEFT-VENTRICULAR VOLUME IN ANIMALS AND HUMANS BY CONDUCTANCE CATHETER
CONTINUOUS MEASUREMENT OF LEFT-VENTRICULAR VOLUME IN ANIMALS AND HUMANS BY CONDUCTANCE CATHETER
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DOI：
10.1161/01.cir.70.5.812
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发表时间：
1984-01-01
期刊：
影响因子：
37.8
通讯作者：
BUIS, B
中科院分区：
文献类型：
--
作者：
BAAN, J;VANDERVELDE, ET;BUIS, B
先前开发并用于确定狗的每搏输出量的8电极电导导管被应用于人类和狗以定量测量绝对左心室容积。为了校准，公式 V(t) = (1/α)(L2/sigma.b)G(t) - Vc，其中 V(t) 是随时间变化的左心室容积 α。是无量纲常数，L是电极间距，σp是通过采样比色皿获得的血液电导率，G(t)是左心室腔内测量的电导率。 Vc 是由空腔周围结构的并联电导引起的校正项，有两种测量方法。第一种方法适用于麻醉动物，包括通过抽吸暂时将体积减少至零。第二种方法通过将一小团高渗盐水（狗）或 10 ml 冷葡萄糖（人）注射到肺动脉中，使用 σb 的瞬时变化。该公式的有效性先前已针对离体死后犬心脏建立。通过将电导体积数据与独立方法的结果进行比较，研究了体内左心室 Vc 的预测线性、斜率常数 α 和准确性：每搏输出量的电磁血流测量和射血分数的指示剂稀释技术（狗）、心输出量的热稀释（12 名患者）和 V(t) 的单平面心室造影（5 名患者）。在所有比较中，线性回归显示出高度相关性（从 r = 0.82 [n = 46] 到 r = 0.988 [n = 20]），而 α（除 1 个例外）范围为 0.75 至 1.07，Vc 误差范围为 0.5% 至 16.5%（平均 7%）。导管定位后，未观察到心律失常。电导导管显然提供了一种可靠且简单的方法来测量左心室容积，提供易于校准的在线时变信号。与通过导管腔获得的左心室压力一起，该仪器可用于瞬时显示压力-容量环，以促进左心室泵性能的评估。
An 8-electrode conductance catheter previously developed and used to determine stroke volume in dogs was applied in human beings and dogs to measure absolute left ventricular volume quantitatively. For calibration the formula V(t) = (1/.alpha.)(L2/.sigma.b)G(t) - Vc, where V(t) is time-varying left ventricular volume, .alpha. is a dimensionless constant, L is the electrode separation, .sigma.p is the conductivity of blood obtained by a sampling cuvette and G(t) is the measured conductance within the left ventricular cavity was developed. Vc is a correction term caused by the parallel conductance of structures surrounding the cavity and is measured in 2 ways. The 1st method, applicable in the anesthetized animal, consists of temporary reduction of volume to zero by suction. The 2nd method uses a transient change in .sigma.b by injection of a small bolus of hypertonic saline (dogs) or 10 ml of cold glucose (humans) into the pulmonary artery. The validity of the formula was previously established for the isolated postmortem canine heart. The predicted linearity, slope constant .alpha., and accuracy of Vc for the left ventricle in vivo were investigated by comparing the conductance volume data with results from independent methods: electromagnetic blood flow measurement for stroke volume and indicator dilution technique for ejection fraction (dogs), thermal dilution for cardiac output (12 patients) and single-plane cineventriculography for V(t) (5 patients). In all comparisons, linear regression showed high correlation (from r = 0.82 [n = 46] to r = 0.988 [n = 20]) while .alpha., with 1 exception, ranged from 0.75 to 1.07 and the error in Vc ranged from 0.5% to 16.5% (mean 7%). After positioning of the catheter, no arrhythmias were observed. The conductance catheter apparently provides a reliable and simple method to measure left ventricular volume, giving an on-line, time-varying signal that is easily calibrated. Together with left ventricular pressure obtained through the catheter lumen, the instrument may be used for instantaneous display of pressure-volume loops to facilitate assessment of left ventricular pump performance.