Preconditioning Does Not Attenuate Myocardial Stunning
Preconditioning Does Not Attenuate Myocardial Stunning
复制标题
预处理不会减轻心肌顿抑
作者：
M. Ovize;K. Przyklenk;S. Hale;R. Kloner
背景：尽管有大量报道称，一次或多次短暂冠状动脉闭塞对心肌进行预处理，并显著减少因随后的长时间缺血而产生的心肌梗死面积，但我们最近证明，预处理并不能减轻梗死周围组织的收缩功能障碍。然而，预适应对心肌的具体影响尚不清楚，在这种情况下，心肌壁运动没有受到预适应方案本身的损害，并进一步受到短暂的缺血损伤（即不与坏死混淆）。方法与结果在犬心肌休克模型中探讨了这些问题。18只麻醉犬进行15分钟冠状动脉闭塞后3小时再灌注。在15分钟冠状动脉闭塞前，每只狗接受三种治疗中的一种：不干预（对照组，n=6），一次5分钟冠状动脉闭塞/ s分钟再灌注（PC5组，n=6），或一次2.5分钟冠状动脉闭塞/ s分钟再灌注（PC25组，n=6）。采用超声测量法监测缺血/再灌注心肌节段缩短（SS），注射放射性标记微球测定心肌血流量。冠状动脉闭塞15分钟时，三组心肌缺血程度相同：对照组、PC25组和PC5组心肌中血流平均值分别为0.05±0.02、0.07±0.04和0.08±0.03 ml/min/g。在冠状动脉闭塞15分钟前，PC5犬表现出显著的休克（SS=55%基线；与对照组相比p<0.01），而PC25犬没有（SS=91%基线；p=NS与对照组相比）。然而，在随后的15分钟冠状动脉闭塞期间，三组的节段缩短同样被抑制，为基线值的- 25%至- 42%。此外，所有三组在再灌注后均表现出相似程度的休克：在回流后3小时，对照组、PC25组和PC5组的SS分别为基线的24±12%、34±16%和48±12% （p=NS）。冠状动脉闭塞时心肌中血流量与再灌注后功能恢复程度相关。然而，这种关系在三组之间并没有什么不同：具体来说，对于缺血期间任何给定的侧支血流，预处理都没有降低休克程度。结论预处理既不能保留可逆性缺血损伤时的收缩功能，也不能防止心肌在血流初期休克。
BackgroundDespite numerous reports that one or more episodes of brief coronary artery occlusion preconditions the myocardium and dramatically reduces myocardial infarct size produced by a subsequent prolonged ischemia, we recently demonstrated that preconditioning does not attenuate contractile dysfunction in the peri-infarct tissue. However, the specific effects of preconditioning on myocardium in which wall motion has not been compromised by the preconditioning regimen per se and is further submitted to a short ischemic insult (that is, not confounded by necrosis) remain unknown. Methods and ResultsWe addressed these issues in the canine model of myocardial stunning. Eighteen anesthetized dogs underwent 15 minutes of coronary occlusion followed by 3 hours of reperfusion. Before the 15-minute coronary occlusion, each dog received one of three treatments: no intervention (control group, n=6), one episode of 5-minute coronary occlusion/S-minute reperfusion (PC5 group, n=6), or one episode of 2.5-minute coronary occlusion/S-minute reperfusion (PC25 group, n=6). Segment shortening (SS) in the ischemic/reperfused midmyocardium was monitored by sonomicrometry, and myocardial blood flow was assessed by injection of radiolabeled microspheres. All three groups were equally ischemic during the 15-minute coronary occlusion: Midmyocardial blood flow averaged 0.05±0.02, 0.07±0.04, and 0.08±0.03 ml/min/g in control, PC25, and PC5 groups, respectively. Before the 15-minute coronary occlusion, PC5 dogs exhibited significant stunning (SS=55% baseline; p<0.01 versus control), whereas PC25 dogs did not (SS=91% baseline; p=NS versus control). However, segment shortening during the subsequent 15-minute coronary occlusion was equally depressed at −25% to −42% of baseline values among the three groups. Furthermore, all three groups demonstrated a similar degree of stunning after reperfusion: SS at 3 hours after reflow averaged 24±12%, 34±16%, and 48±12% of baseline in control, PC25, and PC5 groups, respectively (p=NS). The degree of recovery of function after reperfusion correlated with the amount of midmyocardial blood flow during coronary artery occlusion. However, this relation was not different among the three groups: Specifically, for any given collateral flow during ischemia, preconditioning did not reduce the degree of stunning. ConclusionsPreconditioning neither preserves contractile function during a reversible ischemic insult nor prevents myocardial stunning during the initial hours of reflow.
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影响因子：
24
作者：
K. Przyklenk;R. Kloner
通讯作者：
K. Przyklenk;R. Kloner
重复短暂缺血发作后的局部心肌功能：改变再灌注期持续时间的影响。
影响因子：
4.8
作者：
Wynsen,JC;Kenny,D;Brooks,HL;Warltier,DC
通讯作者：
Warltier,DC
犬可逆性心肌缺血损伤后，由于腺嘌呤核苷酸的再合成延迟，导致 ATP 和腺嘌呤核苷酸库的长期消耗。
影响因子：
5
作者：
Reimer,KA;Hill,ML;Jennings,RB
通讯作者：
Jennings,RB
DOI：
--
发表时间：
1985-12
期刊：
The American journal of pathology
影响因子：
--
作者：
M. T. Vivaldi;R. Kloner;F. Schoen
通讯作者：
M. T. Vivaldi;R. Kloner;F. Schoen
影响因子：
20.1
作者：
MURRY, CE;RICHARD, VJ;JENNINGS, RB
通讯作者：
JENNINGS, RB