Furberg C D, Byington R P
Cardiovasc Clin. 1989;20(1):235-48.
Beta-blockers given within the first 24 hours of an acute MI, first as an intravenous bolus followed by oral therapy, have been shown to reduce in-hospital mortality following a myocardial infarction. For the long-term, beta-blockers represent the only documented effective prophylactic treatment for MI patients. The reduction in all-cause mortality is due primarily to a reduction in atherosclerotic cardiovascular deaths, particularly sudden cardiac deaths. This finding is consistent with the experimental observation that beta-blockers raise the threshold for ventricular fibrillation. Indeed, MI patients with complex ventricular arrhythmias respond very favorably to beta-blockers. However, reductions in nonsudden deaths and nonfatal reinfarctions have also been observed, suggesting that the beneficial effects of beta-blockers are not limited to antiarrhythmic effects alone and that these drugs may also have anti-ischemic effects. The prime candidates for beta-blocker therapy are the high-risk MI patients with transient electrical and/or pump complications during the acute phase. If therapy is initiated within hours of an acute infarction, it seems reasonable to continue it after hospital discharge. Evidence from the large, long-term trials suggest that, in the absence of any troublesome adverse reaction and given that most post-MI patients experience ventricular arrhythmias and angina, it seems reasonable not to limit the duration of treatment.
在急性心肌梗死（MI）的头24小时内给予β受体阻滞剂，首先静脉推注，随后口服治疗，已被证明可降低心肌梗死后的住院死亡率。从长期来看，β受体阻滞剂是唯一有文献记载的对MI患者有效的预防性治疗药物。全因死亡率的降低主要归因于动脉粥样硬化性心血管死亡的减少，尤其是心源性猝死。这一发现与实验观察结果一致，即β受体阻滞剂可提高室颤阈值。事实上，伴有复杂室性心律失常的MI患者对β受体阻滞剂反应良好。然而，非猝死和非致命性再梗死也有所减少，这表明β受体阻滞剂的有益作用不仅限于抗心律失常作用，这些药物可能还具有抗缺血作用。β受体阻滞剂治疗的主要适用对象是急性期出现短暂电和/或泵功能并发症的高危MI患者。如果在急性梗死数小时内开始治疗，出院后继续治疗似乎是合理的。大型长期试验的证据表明，在没有任何麻烦的不良反应的情况下，鉴于大多数MI后患者会出现室性心律失常和心绞痛，不限制治疗持续时间似乎是合理的。
