Physiological relevance of T-tube model parameters with emphasis on arterial compliances.
Physiological relevance of T-tube model parameters with emphasis on arterial compliances.
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T 管模型参数的生理相关性，重点是动脉顺应性。
DOI：
10.1152/ajpheart.1995.269.1.h365
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Miller,DE
中科院分区：
文献类型：
--
作者：
Shroff,SG;Berger,DS;Korcarz,C;Lang,RM;Marcus,RH;Miller,DE
检查全身动脉循环 T 管模型的模型参数的生理相关性。在控制条件下，在麻醉、开胸狗中，在左侧髂外动脉中的球囊膨胀期间（n = 5），以及在输注血管活性药物硝普钠（NTP，n = 4）和去氧肾上腺素（PHL，n = 5）期间，测量主动脉根部压力 [Pao(t)] 和流量 [Qao(t)] 以及降主动脉流量 [Qb(t)]。以 Pao(t) 作为输入，模型在所有条件下 (r2 > 0.96) 都准确预测了 Qao(t) 和 Qb(t)。球囊充气数据建立了模型区分近端和远端动脉机械特性的能力。此外，近端特性（即管特性阻抗和传输时间）独立于远端特性，例如终端顺应性和阻力（或等效地，波反射）。 NTP 和 PHL 的作用在药理学上是一致的，有助于进一步验证该模型。 NTP 主要影响远端（负载）特性，而 PHL 则改变负载和管参数。还讨论了模型参数的生理学解释，特别是顺应性。模型正确区分近端和远端动脉特性的能力是相关的，因为这些特性可能以不同的方式影响心血管功能。
The T-tube model of systemic arterial circulation was examined with respect to the physiological relevance of model parameters. root aortic pressure [Pao(t)] and flow [Qao(t)] and descending aortic flow [Qb(t)] were measured in anesthetized, open-chest dogs under control conditions, during inflation of a balloon positioned in the left external iliac artery (n = 5), and during infusion of vasoactive drugs nitroprusside (NTP, n = 4) and phenylephrine (PHL, n = 5). With Pao(t) as the input, the model accurately predicted both Qao(t) and Qb(t) under all conditions (r2 > 0.96). The balloon inflation data established the ability of the model to discriminate between proximal and distal arterial mechanical properties. Furthermore, proximal properties (i.e., tube characteristic impedances and transit times) were independent of distal properties such as terminal compliances and resistances (or equivalently, wave reflections). The effects of NTP and PHL were pharmacologically consistent and served to further validate this model. NTP primarily affected distal (load) properties, whereas PHL altered both load and tube parameters. Physiological interpretation of model parameters, particularly compliance, is also discussed. The ability of the model to correctly discriminate between proximal and distal arterial properties is relevant because these properties may affect cardiovascular function differently.