組織の不連続は,伝導速度回復に影響する:構造的障壁が波打破を促進するメカニズムである
Richard Derksen1, Harold V M van Rijen, Ronald Wilders
1Heart Lung Center Utrecht, University Medical Center, Utrecht, Netherlands.
Circulation
|July 16, 2003
まとめ
構造的障壁は,心臓の電気波の伝播を妨害する組織不連続性を生み出します. この研究は,これらの不連続が異常な伝導速度回復を引き起こし,心臓病における波の破裂とを潜在的に説明することを示しています.
科学分野:
- 心臓電気生理学 心臓電気生理学
- バイオフィジックス 生物物理学
- セルラー心臓病学 セルラー心臓病学
背景:
- 心波の破裂とを促す構造的障壁の役割は不明である.
- 伝導速度 (CV) の復元は波折の重要な要因であり,その異常は心疾患,特に繊維組織における心室細動と関連しています.
- 構造的な障壁は,異常なCV復元につながる組織不連続を課す可能性があります.
研究 の 目的:
- 構造的障壁によって引き起こされる組織不連続が異常な伝導速度回復につながるという仮説を調査する.
- 組織不連続性における異常なCV回復の基礎となる細胞機構を解明する.
主な方法:
- 新生ネズミの心臓細胞培養を用いたシミュレートされた組織不連続は,8本の腕の星パターンで.
- 早期刺激を施し,細胞外電図とアクションポテンシャルを複数の部位で記録した.
- ボルテージクランプの測定とコンピュータシミュレーションを使用して,シミュレートされた不連続性における脱極化電流を分析しました.
主要な成果:
- 活性化遅延の漸進的な増加は,異常なCV回復を示唆し,特に組織不連続で観察されました.
- アクティベーションの遅延は,恒星中心の近接 (0.81 ms/10 ms) と比較して,遠距離 (3.13 ms/10 ms) の不連続性において有意に大きかった.
- ボルテージクランプとシミュレーションにより,デポラライゼーション電流の二相,長期の活性化と遅延の無活性化が観測された遅延に寄与することを明らかにしました.
結論:
- 組織の不連続は,異常な伝導速度回復を引き起こすことが実証されています.
- 異常復元は,初期遅い活性化後に活性化の急速な増加と,不連続性におけるデポラージング電流の遅い無活性化によるものです.
- これらの発見は,構造的障壁,異常な心筋回路回復,および動のような心律不整の潜在的な可能性との間のメカニズム的リンクを提供します.
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