ナトリウムチャネル変異と心不全や心房細動への感受性
Timothy M Olson1, Virginia V Michels, Jeffrey D Ballew
1Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA. olson.timothy@mayo.edu
JAMA
|January 27, 2005
まとめ
SCN5Aの遺伝的欠陥は,拡張性心筋症 (DCM) と心房細動に関連しています. これらの変異は,早期発症した心不全や家族内のリズム障害を引き起こす可能性があります.
科学分野:
- 心血管遺伝学 心血管遺伝学
- 分子心臓病学 分子心臓病学
背景:
- 拡張性心筋病 (DCM) は,複雑な遺伝性心疾患である.
- 多くのDCM遺伝子が構造タンパク質に影響する一方で,イオンチャネルを含む新しいメカニズムが浮上しています.
- DCMの完全な遺伝的景観は,まだ完全に理解されていません.
研究 の 目的:
- 既知の位置で新しいDCM遺伝子を特定する.
- DCM患者のコホートにおけるSCN5A変異の特徴.
- 変異媒介の親族におけるDCMの流行を評価する.
主な方法:
- 染色体3pのDCMの位置を微細にマッピングした.
- 候補遺伝子の突然変異を検知するために156人のDCMプロンダをスクリーニングしました.
- 評価された親戚は,エコーカルディオグラフィー,ECG,DNA分析.
主要な成果:
- 心臓のナトリウムチャネルをコードするSCN5Aは,候補遺伝子として特定されました.
- いくつかのSCN5A変異 (ミッセンセと断片) が発見され,DCM,心房細動,伝導欠陥と分離しました.
- SCN5A変異を有する個人は,早期発症のDCMおよび心房細動を含む変数表現性を示しました.
結論:
- 遺伝性SCN5A変異は,早期発症のDCMと心房細動に個人を誘発する.
- SCN5Aの欠陥は,心不全,心律乱,またはその両方として現れます.
- これは,DCMの病原性におけるナトリウムチャネル機能障害の役割を強調しています.
関連する概念動画
Heart Failure II: Pathophysiology
658
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...
658
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
2.7K
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,...
2.7K
Voltage-gated Ion Channels
10.2K
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several...
10.2K
Mechanism of Cardiac Arrhythmias
1.6K
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.
1.6K
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
1.5K
Class IV antiarrhythmic drugs, such as verapamil and diltiazem, block calcium channels. They primarily affect the heart, slowing the conduction in calcium-dependent tissues like the SA and AV nodes. These drugs manage reentrant supraventricular tachycardia (SVT) and reduce ventricular rate in atrial flutter/fibrillation.
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
1.5K
Heart Failure Drugs: Diuretics
763
Heart failure and kidney perfusion are interconnected in a complex way. Reduced renal perfusion and venous congestion are two significant factors that contribute to renal dysfunction in heart failure. The kidneys, primarily responsible for fluid balance in the body, are adversely affected due to compromised cardiac output and increased venous pressure. In response to reduced renal perfusion, the kidneys activate neurohumoral mechanisms to restore balance. However, these mechanisms can be...
763


