Campbell K B, Burattini R, Bell D L, Kirkpatrick R D, Knowlen G G
Department of Veterinary and Comparative Anatomy, Physiology, and Pharmacology, Washington State University, Pullman 99164-6520.
Am J Physiol. 1990 Jun;258(6 Pt 2):H1761-74. doi: 10.1152/ajpheart.1990.258.6.H1761.
An asymmetric T-tube model of the arterial system with complex terminal loads was formulated in the time domain. The model was formulated to allow it to be fitted to the aortic pressure waveform, the aortic flow waveform, or simultaneously to both the aortic and descending aortic flow waveforms. Pressure and flow measurements were taken in anesthetized open-chest dogs under basal, vasoconstricted, and vasodilated states. It was found that the T-tube model fitted the data well in all formulations and in all vasoactive states. However, all parameters were estimated accurately in all vasoactive states only with the formulation that fitted to both aortic and descending aortic flow simultaneously. The T-tube model was compared with the three-element windkessel model with regard to the respective models' ability to recreate specific aspects of the pressure waveform and with regard to the estimates of global arterial parameters. The T-tube model recremated those features of the pressure waveform, such as diastolic waves, that the windkessel model could not. Also, the T-tube model systematically estimated lower global arterial compliance and higher characteristic impedance than the windkessel. It was argued that the T-tube model accurately represented important wave transmission features of the arterial loading system. The model is recommended for use in characterizing the arterial load and for merging with representations of the left ventricle in studies of left ventricle-systemic arterial interaction.
在时域中建立了一个具有复杂终端负荷的动脉系统不对称T形管模型。该模型的建立是为了使其能够拟合主动脉压力波形、主动脉血流波形，或同时拟合主动脉和降主动脉血流波形。在基础状态、血管收缩状态和血管舒张状态下，对麻醉开胸犬进行压力和流量测量。结果发现，T形管模型在所有公式和所有血管活性状态下都能很好地拟合数据。然而，只有同时拟合主动脉和降主动脉血流的公式才能在所有血管活性状态下准确估计所有参数。将T形管模型与三元风箱模型在各自重现压力波形特定方面的能力以及全局动脉参数估计方面进行了比较。T形管模型重现了风箱模型无法重现的压力波形特征，如舒张波。此外，与风箱模型相比，T形管模型系统地估计出较低的全局动脉顺应性和较高的特性阻抗。有人认为，T形管模型准确地代表了动脉负荷系统的重要波传播特征。建议该模型用于表征动脉负荷，并在左心室-体循环动脉相互作用研究中与左心室表征相结合。
