Smalling R W
Herz. 1986 Feb;11(1):26-32.
Currently there is no accepted method for measurement of myocardial infarct size in humans. Analysis of both global and regional left ventricular function provides an indirect indication of extent of myocardial necrosis. Acute coronary occlusion results in cessation of function and in some cases dilatation of the involved myocardial segment. Often there is reciprocal hyperfunction of the non-ischemic segments resulting in little impairment of global ventricular function. Average global left ventricular function does not change from hospital admission through hospital discharge in patients with acute myocardial infarction, treated conventionally. With successful coronary reperfusion, however, both regional and global ventricular function have been reported to improve over several weeks after the initial ischemic insult. Improvement in ventricular function is most likely to occur in patients with collaterals or some preservation of antegrade flow to the involved myocardial segment who successfully undergo reperfusion. Return of function occurs in 82% of patients successfully treated within two hours after onset of chest pain. Approximately 50% of patients successfully treated two to 18 hours after onset of chest pain have demonstrated significant improvement in function. Patients admitted with normal ventricular function are less likely to demonstrate improved global ventricular function than those admitted with ejection fractions less than 45%. Acute PTCA with or without thrombolysis may result in a greater return in function than thrombolysis alone. Delayed revascularization more than 48 hours after successful reperfusion does not appear to affect ventricular function a late follow-up but may improve probability of survival. Patients discharged with ejection fractions greater than 45% clearly have an improved prognosis compared to those with depressed ejection fractions post-myocardial infarction.
目前尚无被广泛认可的测量人类心肌梗死面积的方法。对整体和局部左心室功能进行分析可间接反映心肌坏死的程度。急性冠状动脉闭塞会导致心肌功能停止，在某些情况下，梗死心肌节段会出现扩张。通常非缺血节段会出现代偿性功能亢进，导致整体心室功能受损较小。接受传统治疗的急性心肌梗死患者从入院到出院期间，整体左心室功能平均无变化。然而，成功实现冠状动脉再灌注后，据报道局部和整体心室功能在最初缺血损伤后的数周内均有所改善。心室功能改善最有可能发生在存在侧支循环或梗死心肌节段仍有一定顺行血流灌注且成功接受再灌注的患者身上。胸痛发作后两小时内成功接受治疗的患者中，82%的患者心肌功能得以恢复。胸痛发作后两至18小时成功接受治疗的患者中，约50%的患者心肌功能有显著改善。入院时心室功能正常的患者相较于入院时射血分数低于45%的患者，整体心室功能改善的可能性更小。无论是否进行溶栓治疗，急性经皮冠状动脉腔内血管成形术（PTCA）可能比单纯溶栓治疗更能促使心肌功能恢复。成功再灌注后超过48小时进行延迟血管重建，在晚期随访中似乎并不影响心室功能，但可能提高生存率。心肌梗死后出院时射血分数大于45%的患者，与射血分数降低的患者相比，预后明显改善。
