Williams J F, Potter R D
J Clin Invest. 1974 Dec;54(6):1266-72. doi: 10.1172/JCI107871.
The contractile function of right ventricular papillary muscles from normal cats and cats in which the pulmonary artery had been constricted for 6 or 24 wk was examined. Acute pulmonary artery constriction reduced cross-sectional area by an average of 70%, resulting in a 30% mortality from congestive heart failure, all such deaths occurring within the first 3 wk after banding. The increase in right ventricular mass in animals surviving for 6 or 24 wk was similar, averaging 70%. No banded animals had evidence of congestive heart failure at the time of sacrifice, and cardiac output and right atrial pressures were similar to those in control animals.6 wk after banding, the active length-tension curve, maximal rate of rise of isometric force, force-velocity relations, and isometric force with paired stimulation and norepinephrine were all significantly depressed when compared to their respective values in control animals. In contrast, none of these variables was significantly different from control values in animals banded for 24 wk. These observations indicate that depressed contractile state is not a fundamental characteristic of pressure-induced hypertrophied myocardium and reemphasize the important temporal relationship between contractile state and the imposition of sudden sustained loads.
研究了正常猫以及肺动脉已被缩窄6周或24周的猫的右心室乳头肌的收缩功能。急性肺动脉缩窄使横截面积平均减少70%，导致30%的动物死于充血性心力衰竭，所有这些死亡均发生在结扎后的前3周内。存活6周或24周的动物右心室质量增加相似，平均增加70%。在处死时，没有结扎动物出现充血性心力衰竭的迹象，心输出量和右心房压力与对照动物相似。与对照动物各自的值相比，结扎6周后，主动长度-张力曲线、等长力的最大上升速率、力-速度关系以及成对刺激和去甲肾上腺素作用下的等长力均显著降低。相比之下，在结扎24周的动物中，这些变量均与对照值无显著差异。这些观察结果表明，收缩状态降低不是压力诱导肥厚心肌的基本特征，并再次强调了收缩状态与突然持续负荷施加之间重要的时间关系。
