Murgo J P, Westerhof N
Circ Res. 1984 Jun;54(6):666-73. doi: 10.1161/01.res.54.6.666.
Input impedance of the pulmonary arterial system was determined in 10 subjects undergoing elective cardiac catheterization. No cardiovascular or pulmonary disease was found in these patients. In five of the subjects, systemic arterial impedance was also obtained, so that both systems could be compared. Pulmonary and systemic peripheral resistances were 79 +/- 9 dynes sec/cm5 (mean +/- SEM) and 1016 +/- 50 dynes sec/cm5, respectively. Characteristic impedance of the pulmonary circulation was lower than the characteristic impedance of the systemic circulation: 20 +/- 1 dynes sec/cm5 vs. 47 +/- 9 dynes sec/cm5, respectively. Pulmonary pressure and flow spectra for both systems are also presented. The amplitudes of the harmonics of pressure and flow are smaller for the pulmonary circulation, which is consistent with the lower pressures and more rounded waveforms of the normal pulmonary circulation. In all 10 subjects, input impedance of the pulmonary system was examined during both the inspiratory and expiratory phases of respiration. There was no difference between inspiration and expiration in either pulmonary vascular resistance (77 +/- 10 dynes sec/cm5 vs. 80 +/- 9 dynes sec/cm5, respectively), characteristic impedance (20 +/- 1 dynes sec/cm5 vs. 20 +/- 1 dynes sec/cm5) or in the overall impedance spectrum. Quiet respiration, thus, has no effect on the pulmonary arterial load, and changes in pressure and flow must result from alterations in right ventricular performance.
在10名接受择期心导管检查的受试者中测定了肺动脉系统的输入阻抗。这些患者未发现心血管或肺部疾病。在其中5名受试者中，还获得了体动脉阻抗，以便对两个系统进行比较。肺和体循环的外周阻力分别为79±9达因秒/厘米⁵（平均值±标准误）和1016±50达因秒/厘米⁵。肺循环的特征阻抗低于体循环的特征阻抗：分别为20±1达因秒/厘米⁵和47±9达因秒/厘米⁵。还给出了两个系统的肺压和血流频谱。肺循环中压力和血流谐波的幅度较小，这与正常肺循环中较低的压力和更圆润的波形一致。在所有10名受试者中，在呼吸的吸气和呼气阶段都检查了肺系统的输入阻抗。吸气和呼气时，肺血管阻力（分别为77±10达因秒/厘米⁵和80±9达因秒/厘米⁵）、特征阻抗（20±1达因秒/厘米⁵和20±1达因秒/厘米⁵）或整体阻抗谱均无差异。因此，平静呼吸对肺动脉负荷没有影响，压力和血流的变化必定是右心室功能改变所致。
