Stunned myocardiumに関する局所壁動態の研究:Preconditioningの存在はドブタミンに対する心筋動態を変えるか?

顿挫心肌局部壁动力学研究：预处理的存在是否会改变多巴酚丁胺反应的心肌动力学？

• 批准号: 08670783
• 负责人: 久萬田 俊明
• 金额: $ 1.22万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08670783/
• 关键词: myocardial stunning; preconditioning; regional function; dobutamine; reperfusion; myocardial ischemia

Preconditio ningの有無により虚血後心筋機能障害(stunning)の回復過程に差があるか否かをドブタミン(以下DOB)に対する反応性により検討した。【方法】28匹の雑種麻酔開胸犬の左前下降枝に結紮用テープを装着し心筋虚血作成用とした。一対の超音波クリスタルを虚血領域、及び冠動脈回旋枝灌流領域(健常部)の心内膜下層に各々植え込み心筋長の測定用とした。左冠動脈結紮は10分間行い、結紮解放後(再灌流)のstunning(以下ST群)を観察した。また10分間虚血の7.5分前に施行する2.5分間の虚血(5分間再灌流)をPreconditioning(以下PR群)とした。左室圧はKornigs bergで測定した。28頭をST群(n=14)とPR群(n=14)に分け、ST群とPR群をさらに10分間虚血・その後の再灌流だけの群(STc群:n=7,PRc群:n=7)と再灌流20分後からDOBを60分間持続点滴した群(STd群:n=7,PRd群:n=7)に分けた。4群とも再灌流後80分間観察した。【結果】コントロール時の収縮期心筋短縮率(%L)は、虚血部位および健常部位の各々で4群間(STc,STd,PRc,PRd群)に差はなかった。10分間虚血により、虚血部位は4群とも同程度の収縮期心筋bulgingを生じ、虚血の程度が4群とも同等である事を示した。健常部%Lには虚血中4群間に差はなかった。再灌流後20分、4群の虚血部%Lはコントロール時に比べ平均18.2%だけ回復し、stunningの存在が確認された(4群間に差なし)。DOB投与60分後、STd群とPdR群の左室最大陽性dP/dtはDOB投与前に比べ同程度(141%)上昇し、健常側心筋の%LもDOB前に比べ有意に増加した。この所見はSTdとPRdの両群に同程度の左室心筋収縮性の増強が生じた事を意味する。にも拘わらずDOBによるPRd群の虚血部%Lの増加はSTd群の%Lの増加に比べ有意に劣った(p<0.05)。再灌流80分後のSTc群とPRc群の%Lには差は無かった。STc群とPRc群における健常側心筋の%Lにも有意差は無かった。またSTc群とPRc群間、およびSTd群とPRd群間における収縮期最高血圧と心拍数にも有意差は無かった。【結語】stunned心筋の変力作用に対する反応性は、先行する短時間虚血によって影響を受ける。

Precondition The recovery process of myocardial dysfunction (stunning) after blood deficiency is not the same as the recovery process of cardiac dysfunction (stunning). [Method] The left front descending branch of 28 の雑 kinds of hemp and open chest dogs was ligated and packed with a テープを to make the heart muscle deficiency and blood use a とした. It is used for measuring the length of the heart muscle in the subendocardial layer of the coronary artery circumflex branch perfusion area (normal part) and the subendocardial layer of the ultrasound examination. The left coronary artery was ligated for 10 minutes, and then the ligation and release (reperfusion) were followed by stunning (ST group below). Preconditioning (PR group below) of 2.5 minutes of blood deficiency (5 minutes of reperfusion) was performed before the 10-minute period of blood deficiency. Left ventricular pressure was measured using Kornigsberg. 28 heads were divided into ST group (n=14) and PR group (n=14), ST group and PR group were divided into 10 minutes, and the reperfusion group after 10 minutes (STc group: n=7, PRc group: n=7) and after 20 minutes of reperfusion, intravenous drip was maintained at DOB for 60 minutes (STd group: n=7, PRd group: n=7). 4 groups were observed 80 minutes after reperfusion. [Results] There was a significant difference in the systolic myocardial shortening rate (%L) during the contraction period and between the 4 groups (STc, STd, PRc, PRd group) between the blood deficiency site and the normal site. In 10 minutes, the blood deficiency is the same, the blood deficiency area is the same as the systolic bulging of the heart muscle, and the blood deficiency is the same as the 4 groups. There is a difference between the 4 groups in the healthy and regular part of the blood. 20 minutes after reperfusion, the average recovery rate of 4 groups of empty blood was 18.2%, and the confirmation of the existence of stunning was 18.2%. 60 minutes after DOB injection, the left ventricular maximum positive dP/dt of STd group and PdR group increased to the same degree (141%) as before DOB injection, and the normal side cardiac muscle %L increased significantly before DOB injection.このSeeingはSTdとPRdの両groupにの Left ventricular myocardial contractility のincreasing strength が生じた事をmeaningする.にも気わらずDOBによるPRdgroupのdeficiencyblood department%Lのincrease plusはSTdgroupの%Lのincrease plusに比べmeaningに inferiorった(p<0.05). After 80 minutes of reperfusion, there was no difference in the STc group and the PRc group. STc group and PRc group におけるKen often side heart muscle %L にも intentional difference は无かった. The STc group and the PRc group, the STd group and the PRd group, the highest blood pressure during systole, and the number of heart beats are intentionally different, and there is no difference between them. [Conclusion] Stunned heart muscle has a reactive effect due to the force of the heart muscle, and the first step is due to short-term blood deficiency, which is affected by the blood deficiency.