INSTANTANEOUS PRESSURE-VOLUME RELATIONSHIPS AND THEIR RATIO IN EXCISED, SUPPORTED CANINE LEFT-VENTRICLE
INSTANTANEOUS PRESSURE-VOLUME RELATIONSHIPS AND THEIR RATIO IN EXCISED, SUPPORTED CANINE LEFT-VENTRICLE
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DOI：
10.1161/01.res.35.1.117
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发表时间：
1974-01-01
影响因子：
20.1
通讯作者：
SAGAWA, K
中科院分区：
文献类型：
--
作者：
SUGA, H;SAGAWA, K
我们以前已经在正常射血的犬左心室中证明，E（t），即瞬时压力P（t）与瞬时容积V（t）的时变比值，几乎不受舒张末期容积或主动脉压的影响。目前对离体、支撑的犬心脏标本的研究表明，E（t）对完全等容或欠压心搏都是有效的。通过一种新的容积系统，可以更准确地测量脑室内容积。数据的回归分析表明，瞬时压力-容积关系可用方程P（t）=E（t）近似。[V(t)-Vd]，其中Vd是在大范围的脑室内容积上的经验常数。对于给定的收缩状态，等容和欠压搏动的E（t）曲线相似。当以恒定速率（0.2 μg/min）向冠状动脉内输注去甲肾上腺素或异丙肾上腺素增强该制剂的收缩状态时，E（t）峰值从3.6 mm Hg/ml增加63%，达到峰值E（t）的时间从175 msec缩短10%。我们的结论是，目前的调查证实了我们早期的研究，建立了E（t）和心脏的收缩状态之间的联系。
We have previously shown in the normally ejecting canine left ventricle thatE(t), the time-varying ratio of instantaneous pressure,P(t), to instantaneous volume,V(t), is little affected by end-diastolic volume or aortic pressure. The present study on an excised, supported canine heart preparation indicates that the thesis onE(t) is also valid for either totally isovolumic or auxobaric beats. Intraventricular volume was measured more accurately than it was in the previous study by a new volumetric system. Regression analysis of the data showed that the instantaneous pressure-volume relationship could be approximated by the equationP(t) =E(t).[V(t) -Vd], whereVdis an empirical constant, over a wide range of intraventricular volume. SimilarE(t) curves were obtained from both isovolumic and auxobaric beats for a given contractile state. When the contractile state of the preparation was enhanced by a constant-rate infusion (0.2 µg/min) of norepinephrine or isoproterenol into the coronary artery, the peak magnitude ofE(t) increased 63% from 3.6 mm Hg/ml and the time to peakE(t) shortened 10% from 175 msec. We conclude that the present investigation substantiates our earlier study which established a link betweenE(t) and the contractile state of the heart.