在心房动中进行电气改造. 时间流程和机制
A Goette1, C Honeycutt, J J Langberg
1Carlyle Fraser Heart Center, Atlanta, Ga, USA.
Circulation
|December 1, 1996
概括
前庭电力改造是心房的关键因素,发展迅速,并由细胞内过载驱动. 这个过程缩短了耐火期,有助于疾病的进展.
科学领域:
- 心脏病学 心脏病学
- 电子生理学 电子生理学
- 进行心脏重塑.
背景情况:
- 心房动 (AF) 是一种渐进的疾病.
- 快速的心房率诱导电生理变化,称为电改造,这缩短了耐火期.
- 了解电气改造的机制对于管理AF至关重要.
研究的目的:
- 为了研究心房电力改造的时间进程.
- 阐明电气改造的基本机制.
主要方法:
- 麻醉后的狗经历了7小时的心房节奏在800bpm.
- 测量了有效和绝对耐火期 (ARP和ERP).
- 用电子显微镜分析了经静脉内心活检样本.
主要成果:
- 快速心房节奏显著缩短了ARP和ERP (>10%),表明电气重塑.
- 电气改造发生得很快,超过一半的电气改造在30分钟内发生.
- 维拉帕米尔阻断了重塑,而高血症则加剧了它,这表明起了作用.
结论:
- 耳前电力改造是一种快速,渐进的,潜在的持久现象.
- 自主音调,心房拉伸和能量耗尽并不是主要的驱动因素.
- 速度诱导的细胞内过载是心房电力改造的可能媒介.
相关概念视频
01:19Electrophysiology of Normal Cardiac Rhythm
The normal cardiac rhythm is a synchronized electrical activity that facilitates the regular and coordinated contraction of the heart muscle. This process is essential for efficient blood circulation throughout the body. The fundamental elements involved in establishing and maintaining this rhythm include the unique electrical properties of cardiac muscle cells, the sinoatrial (SA) node's pacemaker function, the specialized conducting system, and the ionic mechanisms underlying each phase of...
01:28Mechanism 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.
01:29Disturbances 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...
01:30Cardiac Action Potential
Cardiac action potentials are essential for proper heart function, enabling the rhythmic contractions needed for adequate blood circulation. Nodal cells and Purkinje fibers, specialized for electrical conduction, generate these action potentials.
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
01:25Dysrhythmias VI: Management of Dysrhythmias
Dysrhythmia management involves a multifaceted approach, incorporating pharmacological treatments, medical procedures, surgical interventions, lifestyle modifications, and patient education.Pharmacological ManagementAntiarrhythmic Drugs:Class I (Sodium Channel Blockers): This class includes quinidine and procainamide, which reduce the speed of impulse conduction in the heart, stabilize the cardiac membrane, and control arrhythmias. Quinidine and procainamide are Class IA agents that prolong the...
01:25ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias
Arrhythmia is a condition characterized by an irregular heart rhythm, with ECG changes that differ based on its origin and nature. The types of arrhythmias discussed below include atrial, junctional, and ventricular arrhythmias.Atrial ArrhythmiasPremature Atrial Complexes (PACs): PACs are early atrial beats caused by stress, caffeine, alcohol, electrolyte imbalances, hypoxia, hyperthyroidism, or certain medications (e.g., bronchodilators and decongestants). The ECG shows early P waves with an...