在有意识的绵羊中,左心室压力过载缩的发展过程中,从补偿性缩转变为内在心肌功能障碍. 缩性功能障碍在缩性功能障碍之前
T Aoyagi1, A M Fujii, M F Flanagan
1Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115.
Circulation
|November 1, 1993
概括
心肌功能障碍在患有大动脉收缩的绵羊中发展,即使有持续的后负荷,随着左心室缩的进展. 在这种压力过载模型中,静缩功能障碍在静缩功能障碍之前出现.
科学领域:
- 心血管生理学心血管生理学
- 进行心脏重塑.
- 心脏衰竭病理生理学 病理生理学
背景情况:
- 大动脉狭窄会导致左心室补偿性缩,可能导致心力衰竭.
- 之前的研究表明正常收缩性与轻度,短期压力过载和功能障碍严重过载.
- 在成年大型动物中,从补偿性缩转变为功能障碍的转变并未得到充分证明.
研究的目的:
- 在成年羊中实验证明从补偿左心室缩过渡到心肌功能障碍.
- 调查左心室功能障碍是由于后负载不匹配或内在心肌问题引起的.
- 为了确定是否在压力过载中先有腹缩功能障碍而先有缩功能障碍.
主要方法:
- 在绵羊中使用在上升性大动脉上的液压收缩器诱导左心室缩.
- 后载荷保持不变,而左心室压力在6周内增加.
- 连续的血液动力学研究,包括β阻塞和甲索胺输注,在匹配的负载条件下评估心肌收缩性.
主要成果:
- 左心室缩增加了41% (左心室与体重的比例).
- 心肌功能障碍,以中壁缩短和缩短速度的减少表示,在第4周和第6周之间发展.
- 负荷独立的收缩率指数在6周后证实了心肌收缩率的降低,而腹筋参数保持不变.
结论:
- 该研究表明,心肌收缩性从正常转变为功能障碍.
- 这种过渡发生在渐进性缩过程中,尽管后负荷不断升高.
- 在这种压力过载模型中,观察到静心功能障碍在静心功能障碍之前.
相关概念视频
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...
Rheumatic Heart Disease I: Introduction
Rheumatic heart disease or RHD is a chronic condition that results from rheumatic fever, causing permanent damage to the heart valves.Etiology and Risk FactorsIt primarily arises from rheumatic fever, an inflammatory disease that can develop after untreated or inadequately treated group A streptococcal (GAS) pharyngitis. Streptococcus spreads through direct contact with oral or respiratory secretions. While the bacteria are the causative agents, factors like malnutrition, overcrowding, poor...
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...
Cardiomyopathy IV: Restrictive Cardiomyopathy
Restrictive cardiomyopathy (RCM) is a rare heart muscle disease characterized by impaired ventricular filling due to stiffened ventricular walls, leading to significant diastolic dysfunction.EtiologyRestrictive cardiomyopathy can arise from both inherited and acquired diseases, many of which are systemic. It is categorized into four main types: infiltrative, storage, non-infiltrative, and endomyocardial diseases.Infiltrative diseases, such as amyloidosis, lead to RCM by depositing amyloid...


