不同质的心室再极化为德国牧羊犬自发性心律失常死亡模型中的心律失常提供了基质
Maria N Obreztchikova1, Eugene A Sosunov, Evgeny P Anyukhovsky
1Department of Pharmacology and Pediatrics, Center for Molecular Therapeutics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
Circulation
|August 27, 2003
概括
德国牧羊犬的异质左心室再极化产生了突然死亡的节律失常基质. 再极化电流 (IKr和IKs) 的空间差异以及它们对类甲醇胺的反应有助于这种风险.
科学领域:
- 心脏病学 心脏病学
- 分子生物学分子生物学
- 兽医医学 兽医医学 兽医医学
背景情况:
- 具有遗传性心律失常的德国牧羊犬可以作为人类类甲基胺依赖性心室性心跳动的模型.
- 调查左心室再极化异质性在休息依赖性心室低心率中的作用至关重要.
研究的目的:
- 为了测试左心室再极化异质性在德国牧羊犬中产生心律失常基质的假设.
- 通过检查再极化电流来理解这种异质性的分子基础.
主要方法:
- 微电极技术用于记录来自不同左心室 (LV) 壁区域的动作电位 (AP).
- 全细胞电压用于在孤立的LV肌细胞中研究再极化电流 (IKr和IKs).
- 给出异二醇来评估类甲醇胺的反应性.
主要成果:
- 受影响的狗表现出显著的LV动作潜力持续时间 (APD) 异质性,与不受影响的狗不同.
- 异二醇在患病的狗中对APD产生了差异性的影响,使其在底部缩短,并在底部延长.
- 与未受影响的狗相比,受影响的狗表现出降低的基IKr和改变的IKs激活.
结论:
- 在IKr和IKs表达和catecholamine响应的空间异质性导致异质的LV再极化.
- 这种异质再极化是患有德国牧羊犬的节律失常基质的关键组成部分.
- 这些发现为遗传性心律失常和突然死亡机制提供了洞察力.
相关概念视频
Mechanism of Cardiac Arrhythmias
Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.
Disturbances in Heart Rhythm
Arrhythmia or dysrhythmia refers to an abnormal heart rhythm caused by a defect in the heart's conduction system. It can cause the heart to beat irregularly, too quickly, or too slowly, leading to symptoms like chest pain, shortness of breath, and fainting. Factors such as stress, caffeine, alcohol, nicotine, cocaine, certain drugs, congenital defects, diseases, and electrolyte abnormalities can trigger arrhythmias.
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Dysrhythmias I: Introduction
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Dysrhythmias II: Classification of Tachyarrhythmias
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Dysrhythmias III: Characteristics of Dysrhythmias
Dysrhythmias, also known as arrhythmias, are irregular heart rhythms that result from abnormal electrical activity in the heart, affecting its ability to circulate blood efficiently. Tachyarrhythmias, a subset of dysrhythmias, are characterized by abnormally fast heart rates exceeding 100 beats per minute. Here are some types of tachyarrhythmias with their distinct ECG features:Sinus Tachycardia:Sinus tachycardia presents a regular heart rhythm with an increased rate of 101-180 beats per minute.
Dysrhythmias IV: Characteristics of Bradyarrhythmias
Bradyarrhythmias are cardiac rhythm disorders characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute. Some of which are discussed here:Sinus BradycardiaSinus bradycardia presents a heart rate lower than 60 beats per minute, with a regular rhythm originating from the SA node. The ECG typically shows normal P waves preceding each QRS complex, a normal PR interval (0.12 to 0.20 seconds), and a normal QRS duration (0.06 to 0.10 seconds).First-Degree AV...


