是tau 是一个独立于预负荷的等离体体宽松度的度量吗?
S K Varma1, R M Owen, M L Smucker
1Department of Internal Medicine, University of Virginia School of Medicine, Charlottesville.
Circulation
|December 1, 1989
概括
心肌的延长在心脏病中观察到,但其原因尚不清楚. 这项研究发现,在健康个体中降低预负荷并没有改变,这表明它反映了异常生理学,而不仅仅是心脏负荷.
科学领域:
- 心脏病学 心脏病学
- 身体生理学 身体生理学
背景情况:
- 心肌的延长是各种心肌疾病中已知的发现.
- 长期的原因仍然不确定,争论的是它是否反映了异常的心肌生理学或与疾病相关的过度负荷.
研究的目的:
- 在健康个体中研究预负载的孤立降低对心肌的效果.
- 要确定长时间的TAU是否表明心肌生理异常或心脏工作量增加的结果.
主要方法:
- 在发生反射变化之前,六名健康患者接受了下静脉塞,以诱导预负荷的孤立减少.
- 用基于计算机的数字化程序分析心脏收缩.
- 心肌的值是使用对数 (TL),导数 (TD) 和米尔斯基 (T1/2) 方法在预负荷减小之前和之后计算的.
主要成果:
- 下腔静脉封闭成功地降低了左心室末端透缩压力,而没有显著改变左心室缩压力或心率.
- 在预加载的孤立降低后,没有观察到tau (TL,TD或T1/2) 的显著变化.
- 来自异体度放松的额外推算基线压力保持不变.
结论:
- 在健康个体中,单独降低预负荷不会改变心肌电量.
- 这些发现表明,延长的TAU可能代表心肌生理异常,而不是仅仅是心脏负荷增加的结果.
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