Kamiya A, Yamakoshi K, Shibata M, Kawarada A, Shimazu H
Heart Vessels. 1986;2(2):91-101. doi: 10.1007/BF02059962.
A theoretical analysis of the step response in the closed cardiovascular system induced by a sudden shift of the right cardiac output curve predicted that if the relations of the right heart output (COr) and the total systemic capillary flow (CFs) to the systemic venous pressure (Psv) are linear, then the time course of Psv change will become monoexponential with a time constant T given by T = Csv/(Gr + Gs), where Csv is the systemic vein compliance and Gr and Gs are the conductances of the transient COr-Psv and CFs-Psv relationships. A similar prediction was obtained for the time constant T of the pulmonary vein pressure (Ppv) response to the step change in the left cardiac output (COl) curve, pulmonary vein compliance (Cpv) and the conductances of the COl curve, and the pulmonary capillary flow (CFp) curve against Ppv. The actual Psv or Ppv changes following sudden alteration of the COr or COl curve by inflation and deflation of the balloon in the right or left atrium revealed monoexponential time courses. Semilogarithmic plots of the transient vein pressure changes yielded correlation coefficients of -0.995 +/- 0.006 (means +/- SD) in 11 curves for Psv and 0.977 +/- 0.017 in 16 curves for Ppv (P less than 0.01). The assumed linearity of dynamic COr and COl curves was confirmed by beat by beat COr-Psv and COl-Ppv relationships during the step responses, except for the first few beats immediately after the balloon maneuver. The linearity of the dynamic CFs curve was examined by measuring CFs with a double-step balloon maneuver so as to cause rapid equilibrium between COr and CFs at varied moments of the transient process. The correlation coefficient between CFs and Psv thus obtained was 0.98 +/- 0.04 (P less than 0.01). A similar linearity of the dynamic CFp-Ppv relationship was suggested from their steady-state curves. The values of Csv calculated from the experimental data were 1.70 +/- 0.12 ml/mmHg/kg body wt in 11 curves and those of Cpv were 0.13 +/- 0.03 ml/mmHg/kg in 15 curves. These results are mostly consistent with those previously reported.
对右心输出量曲线突然移位所诱发的封闭心血管系统阶跃响应的理论分析预测，如果右心输出量（COr）和全身毛细血管总血流量（CFs）与体静脉压力（Psv）之间的关系呈线性，那么Psv变化的时间过程将呈单指数形式，其时间常数T由T = Csv/(Gr + Gs)给出，其中Csv是体静脉顺应性，Gr和Gs分别是瞬态COr - Psv和CFs - Psv关系的传导率。对于肺静脉压力（Ppv）对左心输出量（COl）曲线阶跃变化的响应、肺静脉顺应性（Cpv）以及COl曲线和肺毛细血管血流量（CFp）曲线相对于Ppv的传导率，也得到了类似的时间常数T的预测结果。通过在右心房或左心房内对球囊进行充气和放气来突然改变COr或COl曲线后，实际测得的Psv或Ppv变化呈现出单指数时间过程。在11条Psv曲线中，瞬态静脉压力变化的半对数图得到的相关系数为 -0.995 +/- 0.006（均值 +/- 标准差），在16条Ppv曲线中为0.977 +/- 0.017（P < 0.01）。除球囊操作后的最初几搏外，通过阶跃响应期间逐搏的COr - Psv和COl - Ppv关系证实了动态COr和COl曲线的假定线性。通过双步球囊操作测量CFs，以便在瞬态过程的不同时刻使COr和CFs之间快速达到平衡，从而检验动态CFs曲线的线性。由此得到的CFs与Psv之间的相关系数为0.98 +/- 0.04（P < 0.01）。从它们的稳态曲线可以看出动态CFp - Ppv关系具有类似的线性。根据实验数据计算得到的11条曲线的Csv值为1.70 +/- 0.12 ml/mmHg/kg体重，15条曲线的Cpv值为0.13 +/- 0.03 ml/mmHg/kg。这些结果与先前报道的结果基本一致。
