Tjon-A-Meeuw L, Hess O M, Nonogi H, Monrad E S, Leskosek B, Krayenbuehl H P
Department of Internal Medicine, University Hospital, Zurich, Switzerland.
Eur Heart J. 1988 Sep;9(9):1018-26. doi: 10.1093/oxfordjournals.eurheartj.a062593.
Left ventricular (LV) volume was determined simultaneously by monoplane cineangiocardiography and conductivity using a multielectrode conductance catheter at rest and during pressure loading in seven mongrel dogs (mean body weight 22 kg). LV volumes were calculated frame-by-frame (75 frames s-1) by angiocardiography and matched with instantaneous volumes obtained by conductivity. There was an excellent correlation between the two techniques at rest (correlation coefficient, r = 0.96) and during pressure loading (r = 0.92) when the data of each dog were pooled. The standard error of estimate of the mean angiographic volume was 4%. The slope of the regression analysis showed a small but significant (P less than 0.01) decrease from 0.365 at rest to 0.289 during pressure loading, whereas the intercept remained unchanged (24 versus 26 ml). Since no calibration for parallel conductivity of the surrounding tissue was performed, LV end-systolic volume was significantly over- and LV ejection fraction significantly underestimated whereas LV end-diastolic volume was estimated correctly by the conductance technique. It is concluded that LV end-diastolic volume can be determined accurately by the conductance technique in dogs. However, LV end-systolic volume is significantly over- and ejection fraction significantly underestimated. Since there is a good correlation between angiocardiography and conductivity, exact determination of LV volumes and ejection fraction is feasible using a correction factor. The change in slope of the regression equation between angiocardiography and conductivity suggests a change in conductivity of the surrounding tissue during pressure loading which limits the application of the conductance catheter to stable haemodynamic situations or calls for repeated calibrations by an independent technique during acute interventions.
在7只杂种犬（平均体重22千克）中，使用多电极电导导管在静息状态和压力负荷期间，通过单平面电影血管造影术和电导法同时测定左心室（LV）容积。通过血管造影术逐帧计算LV容积（75帧/秒），并与通过电导法获得的瞬时容积相匹配。当汇总每只犬的数据时，两种技术在静息状态下（相关系数r = 0.96）和压力负荷期间（r = 0.92）具有极好的相关性。平均血管造影容积估计的标准误差为4%。回归分析的斜率显示出从静息时的0.365到压力负荷期间的0.289有小幅但显著的下降（P < 0.01），而截距保持不变（24对26毫升）。由于未对周围组织的平行电导进行校准，电导技术显著高估了LV舒张末期容积，显著低估了LV射血分数，而LV舒张末期容积估计正确。结论是，电导技术可在犬中准确测定LV舒张末期容积。然而，LV收缩末期容积被显著高估，射血分数被显著低估。由于血管造影术和电导法之间具有良好的相关性，使用校正因子可准确测定LV容积和射血分数。血管造影术和电导法之间回归方程斜率的变化表明，压力负荷期间周围组织的电导发生了变化，这限制了电导导管在稳定血流动力学情况下的应用，或要求在急性干预期间通过独立技术进行重复校准。
