フォントンの生理学における周周周血管適応と正静性耐性
Usha S Krishnan1, Indu Taneja, Michael Gewitz
1Department of Pediatric Cardiology, New York Medical College, Valhalla, NY 10595, USA. usha_krishnan@nymc.edu
Circulation
|October 21, 2009
まとめ
フォンタン循環の患者は,静脈の圧力が高く,血管が硬くなり,流体シフトが減少し,直立の耐性を向上させ,より高い静脈圧力に適応します. これらの変化は,フォントンの循環に血液が戻ってくるのを維持するのに役立ちます.
科学分野:
- 心血管生理学 心血管の生理学
- ペディアトリック・カルディオロジー
- 血管生物学 血管生物学
背景:
- フォントンの循環は,高圧の静脈圧に依存し,効率的な静脈回帰を可能にします.
- 系統静脈圧の慢性的な増加は,特に直立した姿勢では,適応性血管の変化を誘発する可能性があります.
研究 の 目的:
- フォントン後の患者における地域血管と外周血管の適応的変化を調査する.
- これらの適応が,特に直立状態で,心臓の出力を維持する方法を理解する.
主な方法:
- 9人のフォントン後の患者 (13-24歳) と6人の年齢/性別を合わせた対照群を比較した.
- 張力計と阻力プレシスモグラフィーを利用して,外周循環と血液量を測定した.
- ヘッド・アップ・ティルト・テストを用いた循環器反応の評価.
主要な成果:
- フォンタンの患者は,小腿の容量が低く,静脈の静止圧力が高かった.
- フォントンの患者では,足の動脈抵抗性の増加とマイクロ血管の過濾圧の上昇が観察されました.
- フォントンの患者は,対照群と比較して,ヘッドアップの傾き時に,スプラニクスの流れが保存され,スプラニクスの動脈抵抗が鈍化した増加を示した.
結論:
- 静脈適合性の低下と過濾の値の上昇は,フォントンの循環における適応的メカニズムであるようです.
- 十分に補償されたフォンタン患者は,流体シフトの減少とより高い血管抵抗により,優れた正静性耐性を発揮します.
- 静脈の硬さが増加し,スプランキンの容量が変化することは,Fontan患者で立っているときに静脈の回帰を維持するための適応的戦略である可能性があります.
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