選択的自律的封鎖がヒトのT波変数に与える影響
Eric J Rashba1, Michael Cooklin, Karen MacMurdy
1Division of Cardiology, Department of Medicine, University of Maryland at Baltimore, 21201, USA. erashba@medicine.umaryland.edu
Circulation
|February 21, 2002
まとめ
交感神経系の活動は,高リスクの心臓病患者のT波代替 (TWA) 測定に著しく影響を及ぼします. ベータブロッカーの使用はTWAを減少させ,潜在的に心不全による突然死のリスクを下げる可能性があります.
科学分野:
- 心臓病学 心臓病学
- 電気生理学 電気生理学
- 自律神経系とは,自律神経系である.
背景:
- T波変数 (TWA) は,心室動脈不全の脆弱性の重要な非侵襲的マーカーである.
- 冠動脈疾患 (CAD) の患者は心律不良のリスクが高い.
- これらの患者のTWAにおける自律神経系 (ANS) の役割は完全に理解されていません.
研究 の 目的:
- TWA測定に対する自律神経系の影響を調査する.
- 高リスクの冠動脈疾患患者のTWAを評価するために.
- シンパティックまたはパラシンパティックブロックがTWAに影響するかどうかを判断する.
主な方法:
- 左心室機能不全と誘導性心室低心率を有する60人のCAD患者を研究した.
- TWAは,ベースラインおよび交感性阻害 (エスモロール),パラシンパシー性阻害 (アトロピン),または介入なし (コントロール) の後に測定されました.
- 胸前ペースは,TWA測定中に心拍数を標準化するために使用されました.
主要な成果:
- パラシンパシーブロック (アトロピン) と対照条件はTWAの流行を変化させなかった.
- エスモロールによる交感性ブロックはTWA振幅を著しく低下させた (P<0.001).
- エスモロールは,TWAテストの陽性を50% (70%から35%,P<0.05) 減少させた.
結論:
- 自律神経系の調節,特に交感活動の調節がTWAに影響する.
- TWAは,CAD患者のリスク分層化に役立つツールである可能性があります.
- ベータブロッカーは,CAD患者のTWAに好意的な影響を及ぼすことによって,突然の心臓死のリスクを下げる可能性があります.
関連する概念動画
Drugs Acting on Autonomic Ganglia: Blockers
Ganglionic blockers inhibit autonomic activity by blocking nicotinic receptors in the autonomic ganglia, suppressing impulse transmission. These blockers lack selectivity between sympathetic and parasympathetic ganglia and are ineffective as neuromuscular junction antagonists. They can be categorized into two groups:
Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers
β-adrenergic antagonists, or β-blockers, modulate the sympathetic nervous system by targeting β-adrenoceptors and inhibiting catecholamine-mediated sympathetic responses. β-blockers differ in their adrenoceptor subtype affinity, lipophilicity, and α-blocking capabilities. The history of β-blocker development began with the prototype, dichloroisoprenaline, which exhibited partial agonist activity. As a result, propranolol was developed as a pure antagonist but nonselective agent, paving the way...
Adrenergic Antagonists: ɑ and β-Receptor Blockers
Third-generation β-blockers, such as labetalol and carvedilol, represent a significant advancement in managing cardiovascular conditions. Unlike conventional β-blockers, which can induce peripheral vasoconstriction, third-generation drugs block α1 adrenoceptors. This promotes vasodilation through several mechanisms, such as increased nitric oxide production, inhibition of calcium ion entry, opening of potassium ion channels, and antioxidant action. Labetalol, for instance, is clinically...
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class I antiarrhythmic drugs are used to treat various types of arrhythmias or irregular heart rhythms. These drugs block the sodium (Na+) channels in the cardiac cells, thereby affecting the movement of electrical impulses across the heart. Class I antiarrhythmic drugs are divided into three subgroups: Class IA, Class IB, and Class IC, each with distinct mechanisms of action and effects on the heart.
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Adrenergic stimulation generally impacts cardiac rate and rhythm. Specifically, stimulation of the β-adrenoceptors triggers an increase in intracellular calcium ion influx and pacemaker currents, which may cause arrhythmias. Catecholamines like adrenaline also demonstrate β2-adrenoceptor-mediated hypokalemia, impacting cardiac action potential and disrupting the normal cardiac rhythm. Class II antiarrhythmic drugs are β-adrenoceptor antagonists or β-blockers, which indirectly block calcium...
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...


