在短期冠状动脉封闭期间,左心室透析压力-体积关系的负荷依赖性
1Department of Medicine, Bowman Gray School of Medicine, Winston-Salem, N.C. 27103.
Circulation
|February 1, 1991
概括
急性冠状动脉封闭会改变左心室 (LV) 的透静压力-体积关系,变化取决于心脏体积和心周. 这些发现对于理解心脏病发作期间的透缩功能障碍至关重要.
科学领域:
- 心血管生理学心血管生理学
- 心脏机械学 心脏机械学
- 心肌缺血的研究研究心肌缺血.
背景情况:
- 左心室 (LV) 透支压力-体积关系是心脏功能的关键决定因素.
- 急性冠状动脉封闭可以显著损害透静功能.
- 负载条件和心周约束对心脏对缺血的透静反应的影响需要进一步阐明.
研究的目的:
- 在急性冠状动脉封闭期间,研究变化的负载条件对LV静脉压缩压力-体积关系的影响.
- 为了确定心周在调节不同预负载条件下对缺血的 LV 扩张性反应中的作用.
- 为了评估冠状动脉封闭期间 LV 透静室刚度的变化.
主要方法:
- 使用开放胸部的狗模型 (n=18) 配有用于同时测量 LV 压力和体积的仪器.
- 使用冠状动脉内气球膨胀诱导的急性冠状动脉封闭.
- 在稳定状态条件下,在注入德克斯 (改变预负载) 之前和之后,在带有心周和没有心周,以及静脉塞期间,评估了 LV 透静压力-体积环.
主要成果:
- 冠状动脉封闭导致 LV 扩张压力-体积循环向右移动,表明扩张功能发生变化.
- 这些转变的幅度和方向因基线心脏体积和心周的存在而有所不同.
- 德克斯特兰输液增加了LV末端透析压力和体积在闭塞期间的变化,特别是在完好无损的心周.
- 在注入德克斯后的封闭过程中,LV透静腔的刚度增加,这是由心周细胞调节的效应.
- 维纳卡瓦尔封闭取消了观察到的变化,突出显示了预加载的作用.
结论:
- 变化的负载条件在急性冠状动脉封闭期间显著改变左心室透静压力-体积关系.
- 心 perikardium 在影响 LV 扩张应对缺血的过程中起着至关重要的作用,特别是在心脏体积较大时.
- 闭塞期间LV透心室刚度的变化取决于预负荷和心周完整性.
相关概念视频
Regulation of Stroke Volume
The regulation of stroke volume, which is the amount of blood the heart pumps out during each heartbeat, is critical for maintaining a healthy circulatory system. Stroke volume is influenced by three main factors: preload, contractility, and afterload.
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...
Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...
Imbalances in Cardiac Output
The heart's primary function is to pump blood throughout the body, maintaining a balance between blood sent out (cardiac output) and blood returning (venous return). If this balance is disrupted, it can result in congestive heart failure (CHF), a severe condition where the heart becomes an inefficient pump, leading to inadequate blood circulation.
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood...
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood...
Mitral Regurgitation I: Introduction
Mitral regurgitation is characterized by the backward circulation of blood from the left ventricle to the left atrium during systole, a phase of the cardiac cycle when the heart contracts and pumps blood out of the chambers. This abnormal flow occurs primarily due to the dysfunction of the mitral valve or its supporting structures, which include the mitral leaflets, chordae tendineae, annulus, and papillary muscles.Etiology and Mechanisms:Primary Mitral Regurgitation: This type arises from...
Mitral Stenosis I: Introduction
Mitral Valve Stenosis (MVS) is a heart condition where the mitral valve narrows, impeding blood circulation from the left atrium to the left ventricle. The etiology and pathophysiology of this condition are multifaceted, leading to a cascade of cardiovascular complications.Causes of Mitral Valve StenosisRheumatic Heart Disease: It is the main cause of mitral valve stenosis, particularly in developing nations. This condition arises from rheumatic fever, an inflammatory illness resulting from...
Aortic Regurgitation I: Introduction
IntroductionAortic regurgitation is characterized by the backward flow of blood from the aorta into the left ventricle during diastole and arises from the improper closure of the aortic valve. This condition results in left ventricular volume overload and can stem from both acute and chronic etiologies, each contributing uniquely to the disease's progression and symptomatology.Acute and Chronic CausesAcute aortic regurgitation often results from events that suddenly impair the integrity of the...
Heart Failure II: Pathophysiology
Systolic Heart Failure and Compensatory MechanismsSystolic heart failure (also termed HFrEF, Heart Failure with Reduced Ejection Fraction) is the most prevalent type of heart filure. It results in a decreased volume of blood being pumped from the ventricle. The aortic arch and carotid sinuses have baroreceptors that detect reduced blood pressure, triggering the sympathetic nervous system (SNS) to release epinephrine and norepinephrine. Initially, this response aims to boost heart rate and...


