概括
在发生最大血管扩张之前,心肌输液可以显著下降. 内心血管扩张器储备在较低的冠状动脉压力下持续存在,与心上储备不同,在静止条件下.
科学领域:
- 心血管生理学心血管生理学
- 心肌输血动力学 - - 心肌输血动力学
- 冠状动脉的自我调节
背景情况:
- 了解冠状动脉自身调节对于诊断和治疗心肌缺血至关重要.
- 以前的研究还没有完全阐明降低冠状动脉压力和最大血管扩张之间的关系.
- 评估心肌输液储备对于评估冠状动脉疾病的功能意义至关重要.
研究的目的:
- 调查在降低冠状动脉压力下降的区域性心肌输液是否可靠地表明最大血管扩张.
- 为了确定冠状动脉自调节失败,血管扩张储备耗尽的点.
- 为了在不同冠状动脉压力下比较内心和心表血管扩展器储备.
主要方法:
- 开放胸部的狗模型与控制的环动脉冠状动脉压力.
- 测量不同冠状动脉压力 (自发,35毫米升,25毫米升) 的区域心肌血流 (流入).
- 在腺诱导的血管扩张期间评估心肌输液,以确定血管扩张器储备.
主要成果:
- 随着冠状动脉压力降至35mm Hg,心肌输液显著下降,甚至在最大血管扩张之前.
- 在35mmHg的腺注入期间,流量增加,表明剩余的血管扩展剂储备.
- 在25 mm Hg时,流量大大减少,虽然表心储量持续存在,但内心储量没有显著增加,这表明疲劳.
结论:
- 在药理血管扩展剂储备耗尽之前,心肌输液的显著减少可能会发生.
- 内心血管扩张剂储备可以在没有心跳动的情况下持续到冠状动脉压力低于35mm Hg.
- 在这些条件下,内心血管扩张器储备通常会在表心血管扩张器储备之前耗尽.
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