リポラライゼーション・アルターナンは,人間の心房細動に対する脆弱性を明らかにする
Sanjiv M Narayan1, Michael R Franz, Paul Clopton
1VAMC/Cardiology, University of California-San Diego, 3350 La Jolla Village Dr., San Diego, CA 92161, USA. snarayan@ucsd.edu
Circulation
|June 8, 2011
まとめ
アクションポテンシャル持続時間 (APD) の変数におけるビート・トゥ・ビートの振動は,心房動 (AF) の動的基板を明らかにする. これらの代替薬は,対照群と比較して,持続性およびパラキシズム性AF患者においてより容易に発生し,より低い割合で発生します.
科学分野:
- 心臓病学 心臓病学
- 電気生理学 電気生理学
- 心律不整症とは,心律不整症のこと.
背景:
- 人間の心房細動 (AF) の根本的なメカニズムは,異常な再極化,特にアクションポテンシャル持続 (APD) が関与しているため,まだ完全に理解されていません.
- AFの脆弱性のスペクトルが存在し,AFのない個体から,パラキシズマルおよび持続的な形態を持つ個人に及ぶ.
研究 の 目的:
- APDのビート・トゥ・ビート振動,APDのアルターナーと呼ばれる振動がAF基板に寄与するという仮説を検証する.
- APDの代替薬が,異なる患者グループにおけるAFに対する異なる感受性を説明できるかどうかを判断する.
主な方法:
- プログラムされた電気刺激中に33人の被験者 (12人の持続性AF,13人のパラキシズム性AF,8人の対照) の左および右心房APDを記録した.
- ペースは,APDの復元と代替を評価するために,減速するサイクルの長さ (600〜500 ms,その後AFの開始までより速く) で実行されました.
- APDの変数,複雑な振動,および異なるペースでAFの開始の間の関係を分析した.
主要な成果:
- APDの代替薬は,パラキシズム性AF (372±72 ms) と持続性AF (411±94 ms) の患者と比較して,コントロール群 (サイクル長さ218±33 ms) で著しく速い割合で発現しました.
- AF患者では,APDのアルターナーが100-120bpmのペースで発生し,APDの回復とは無関係であった.
- AFに先立つ複雑な振動は,パロキシズム性AFと持続性AFの患者と比較して,対照群で漸進的により速い割合で発生しました.
結論:
- アトリアルAPDの代替剤はAFのダイナミックな基板として機能し,AFがコントロールと比較して持続的および症候性AF患者でより低い割合で最も容易に現れます.
- APDの代替は,一貫してすべての観察されたAFエピソードに先行し,AFが開始されなかったときに欠席していました.
- 細胞メカニズムを明らかにするためにさらなる研究が必要で,APDの代替体は生理学的心拍数に近い.
関連する概念動画
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
01:25ECG 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...
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...
01:28Mechanism 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.
01:18Dysrhythmias 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...
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...