在人类心力衰竭中改变了心肌力力频率关系
L A Mulieri1, G Hasenfuss, B Leavitt
1Department of Physiology and Biophysics, University of Vermont College of Medicine, Medical Center Hospital of Vermont, Burlington 05405.
Circulation
|May 1, 1992
概括
充血性心力衰竭 (CHF) 损害了心肌收缩能力,显示出心肌衰竭中压力产生减少和频率响应改变. 这些内在的心肌问题有助于扩大心肌病的左心室功能异常.
科学领域:
- 心脏病学 心脏病学
- 身体生理学 身体生理学
- 生物化学 生物化学
背景情况:
- 充血性心力衰竭 (CHF),特别是异常扩张性心肌病,在运动期间的左心室 (LV) 功能异常的特征.
- 观察到的异常包括 LV 体积减少,压力上升/下降率降低,心率依赖收缩力强化 (Bowditch treppe) 损害.
研究的目的:
- 调查和量化心肌收缩功能异常在失败与非失败的人类心脏.
- 为了确定内在心肌功能障碍有助于扩大心肌病的异常心室功能.
主要方法:
- 研究了从NYHA类IV失败和非失败的人类心脏中分离的左心室心肌带.
- 在生理温度 (37°C) 和各种收缩频率 (12-240分−1) 下进行了实验.
- 一种使用2,3-butanedione monoxime (BDM) 的新方法保护了心肌带在剖析过程中免受切割伤害.
主要成果:
- 失败的心肌与不失败的心肌相比,产生显著较少的同位数抽动张力 (分别在72分钟和174分钟-1分钟时减少48%和80%),相比于不失败的心肌.
- 峰值张力频率关系发生在心脏衰竭的较低频率 (平均81 ± 22 分钟-1 与174 ± 4 分钟-1 在非失败).
- 虽然非失败的心肌与频率显著增加紧张,但失败的心肌在60-150分钟-1.1之间没有显著变化.
- 紧张率上升和下降,并行抽紧张在非失败的肌肉,但不是失败的肌肉.
结论:
- 心肌收缩率的内在变化,独立于系统因素,有助于扩大心肌病的左心室功能异常.
- 从分离心肌的发现量上与体内测量结果一致,支持心肌功能障碍的主要作用.
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