Charlat M L, O'Neill P G, Hartley C J, Roberts R, Bolli R
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030.
J Am Coll Cardiol. 1989 Jan;13(1):185-94. doi: 10.1016/0735-1097(89)90569-x.
Myocardial reperfusion after reversible ischemia is known to be associated with prolonged abnormalities of systolic contractile function (myocardial "stunning"). However, no information is available regarding the recovery of diastolic function in the stunned myocardium in the conscious state. Accordingly, 10 conscious dogs instrumented with pulsed Doppler thickening probes underwent a 15 min occlusion of the left anterior descending coronary artery followed by 7 days of reperfusion. Regional systolic function was assessed as net systolic thickening fraction. Left ventricular regional diastolic properties were estimated from two variables: the mean rate to half end-diastolic thinning and the late diastolic thinning fraction. Both indexes of diastolic function remained severely impaired after restoration of flow. In general, the recovery of the mean rate to half end-diastolic thinning and of the late diastolic thinning fraction paralleled the recovery of systolic thickening, but the impairment of the mean rate to half end-diastolic thinning was more marked than that of the late diastolic thinning fraction. At 4 h of reperfusion, the values for the mean rate to half end-diastolic thinning and the late diastolic thinning fraction (expressed as percent of baseline) were 57 +/- 5% (p less than 0.001 versus baseline) and 79 +/- 7% (p less than 0.05), respectively, whereas systolic thickening fraction averaged 52 +/- 10% (p less than 0.001). At 24 h, the mean rate to half end-diastolic thinning and the late diastolic thinning fraction were no longer significantly different from baseline, whereas systolic thickening fraction remained decreased at 82 +/- 4% (p less than 0.001) and returned to control values by 48 h. This study demonstrates the presence of profound, prolonged abnormalities of regional diastolic wall thinning after a brief episode of ischemia in the conscious state and expands the concept of myocardial stunning from the traditional notion of impaired systolic performance to that of a global derangement in mechanical function that involves both systolic and diastolic properties.
已知可逆性缺血后的心肌再灌注与收缩性收缩功能的长期异常（心肌“顿抑”）有关。然而，关于清醒状态下顿抑心肌舒张功能的恢复情况尚无相关信息。因此，对10只植入脉冲多普勒增厚探头的清醒犬进行左前降支冠状动脉15分钟闭塞，随后再灌注7天。区域收缩功能通过净收缩增厚分数进行评估。左心室区域舒张特性通过两个变量进行估计：舒张末期变薄至一半的平均速率和舒张末期晚期变薄分数。血流恢复后，舒张功能的两个指标仍严重受损。一般来说，舒张末期变薄至一半的平均速率和舒张末期晚期变薄分数的恢复与收缩增厚的恢复平行，但舒张末期变薄至一半的平均速率受损比舒张末期晚期变薄分数更明显。再灌注4小时时，舒张末期变薄至一半的平均速率和舒张末期晚期变薄分数（以基线百分比表示）分别为57±5%（与基线相比p<0.001）和79±7%（p<0.05），而收缩增厚分数平均为52±10%（p<0.001）。24小时时，舒张末期变薄至一半的平均速率和舒张末期晚期变薄分数与基线不再有显著差异，而收缩增厚分数仍降至82±4%（p<0.001），并在48小时恢复至对照值。本研究表明，清醒状态下短暂缺血后区域舒张壁变薄存在深刻、长期的异常，并将心肌顿抑的概念从传统的收缩功能受损观念扩展到涉及收缩和舒张特性的机械功能全面紊乱。
