Left ventricular volume measurement by conductance catheter in intact dogs. Parallel conductance volume depends on left ventricular size.
Left ventricular volume measurement by conductance catheter in intact dogs. Parallel conductance volume depends on left ventricular size.
复制标题
通过电导导管测量完整狗的左心室容积。
DOI：
10.1161/01.cir.80.5.1360
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发表时间：
1989
期刊：
影响因子：
37.8
通讯作者：
Glantz,SA
中科院分区：
文献类型：
--
作者：
BoltwoodJr,CM;Appleyard,RF;Glantz,SA
电导导管是一种很有前途的连续测量左心室容积的新仪器。绝对LV容积（V[t]）与未校正的传导容积B（t）相关，公式为：V（t）=（1/α）（B（t）-α Vc）。α Vc因子表示LV血池外导电材料引起的平行电导体积，可通过推注高渗盐水瞬时改变血液电导率来估计。α是B（t）与真实LV容积之间关系的斜率。我们测试了α Vc和α在一系列血流动力学条件下保持恒定的假设。在对照条件下以及随后的下腔静脉（IVCO）、主动脉（AO）和肺动脉（PAO）暂时球囊闭塞期间，我们对7只完整犬进行了多次高渗盐水α Vc测定。我们还比较了在类似的控制和介入条件下的B（t）与同步双平面血管造影LV容积。对照期间，生理盐水衍生的α Vc为76 +/- 2 ml，IVCO期间显著下降-7 +/- 2 ml（p <0.001），但AO或PAO期间未下降。根据多元线性回归分析，生理盐水衍生的α Vc的最强预测因子是未校正的收缩末期Bes，灵敏度系数为0.60 +/- 0.06 ml/ml（p <0.001）。血管造影衍生的α Vc显示出对Bes的相似依赖性，系数为0.77 +/- 0.14 ml/ml（p <0.001）。血管造影测定的α也显示出血流动力学干预的显著变化，主要反映了对α Vc的潜在依赖性。α Vc和α随LV尺寸的变化可能源于B（t）-V（t）关系中的非线性。尽管电导导管提供了相对LV容积的有用测量，但使用恒定α Vc和α因子在宽血流动力学范围内测量绝对LV容积是不现实的。这一结果对目前使用该技术测量绝对收缩末期-压力-容积关系提出了质疑。
The conductance catheter is a promising new instrument for continuously measuring left ventricular (LV) volume. Absolute LV volume (V[t]) is related to uncorrected conductance volume, B(t), according to the equation: V(t) = (1/alpha)(B(t) - alpha Vc). The alpha Vc factor represents parallel-conductance volume due to conducting material outside the LV blood pool, and may be estimated by transiently changing blood conductivity using a bolus injection of hypertonic saline. alpha is the slope in the relation between B(t) and true LV volume. We tested the assumption that alpha Vc and alpha are constant over a range of hemodynamic conditions. We performed multiple hypertonic saline alpha Vc determinations in seven intact dogs during control conditions and subsequent temporary balloon occlusions of inferior vena cava (IVCO), aorta (AO), and pulmonary artery (PAO). We also compared B(t) with simultaneous biplane angiographic LV volume during similar control and intervention conditions. The saline-derived alpha Vc was 76 +/- 2 ml during control and fell significantly by -7 +/- 2 ml during IVCO (p less than 0.001) but not during AO or PAO. According to multiple linear regression analyses, the strongest predictor of saline-derived alpha Vc was uncorrected end-systolic Bes, with a sensitivity coefficient of 0.60 +/- 0.06 ml/ml (p less than 0.001). Angiographically derived alpha Vc showed a similar dependence on Bes, with a coefficient of 0.77 +/- 0.14 ml/ml (p less than 0.001). Angiographically determined alpha also showed significant variation with hemodynamic interventions, largely reflecting an underlying dependence on alpha Vc. The variation in alpha Vc and alpha with LV size may stem from nonlinearity in the B(t)-V(t) relation. Although the conductance catheter provides a useful measure of relative LV volume, measurement of absolute LV volume over a wide hemodynamic range using constant alpha Vc and alpha factors is unrealistic. This result calls into question the current use of this technique for the measurement of the absolute end-systolic--pressure-volume relation.