短期的な冠動脈閉塞の間,左心室のダイアストリック圧力-体積関係の負荷依存性
1Department of Medicine, Bowman Gray School of Medicine, Winston-Salem, N.C. 27103.
Circulation
|February 1, 1991
まとめ
急性冠動脈閉塞は,左心室 (LV) の透析圧-体積関係に変化をもたらし,心臓の体積と心帯に依存する変化を起こす. これらの発見は,心臓発作時の下痢性機能不全を理解するために極めて重要です.
科学分野:
- 心血管生理学 心血管の生理学
- 心臓のメカニズム 心臓のメカニズム
- 心筋力衰弱症の研究について
背景:
- 左心室 (LV) の透析圧-体積関係は,心臓機能の決定的な決定因子である.
- 急性冠動脈閉塞は,ダイアストリック機能を著しく低下させる可能性があります.
- 負荷条件と心周束縛が,イシュケミアのダイアストリック応答に及ぼす影響については,さらなる解明が必要である.
研究 の 目的:
- 急性冠動脈閉塞の際に,変異した負荷条件がLVのダイアストリック圧力-体積関係に与える影響を調査する.
- 異なるプレロード条件下でのイシュケミアに対するLVダイアストリック応答を調節するペリカルドの役割を決定する.
- 冠動脈閉塞中のLVダイアストリック室の硬さの変化を評価するために.
主な方法:
- オープンチェストの犬モデル (n=18) を利用し,同時にLV圧力と体積を測定するための計器を装備しました.
- 冠動脈内気気球膨張を用いた誘導された急性冠動脈閉塞.
- デクストラン注入前と後 (前負荷を変えるため),心周膜と心周膜の有無, vena caval occlusion の間,安定状態の条件下で,評価されたLVダイアストリック圧力-体積ループ.
主要な成果:
- 冠動脈閉塞は,LVのダイアストリック圧力-体積ループの右へのシフトを引き起こし,ダイアストリック機能の変化を示しました.
- これらのシフトの大きさと方向は,ベースラインの心臓の体積と心周の存在によって変化しました.
- デクストランの輸注は,閉塞中に,特に心周膜が無傷である場合,LVの末期透析圧と体積のシフトを増加させました.
- デクストラン注入後の閉塞の間,LVダイアストリック室の硬さが増加し,これは perikardiumによって調節される効果です.
- Vena caval occlusionは観測されたシフトを廃止し,プレロードの役割を強調しました.
結論:
- 変化した負荷条件は,急性冠動脈閉塞の際に左心室のダイアストリック圧力-体積関係を大幅に変化させます.
- perikardiumは,特に心臓の体積が高く,イシュケミアに対するLVダイアストリック応答に影響を与える上で重要な役割を果たします.
- 閉塞中のLVダイアストリック室の硬さの変化は,前負荷と心循環器の整合性に依存します.
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