探讨急性心肌梗塞（AMI）介入治疗患者早期应用β受体阻滞剂对心功能和自主神经功能状态的影响。

将经介入治疗的122例AMI患者，根据有无早期使用β受体阻滞剂分为对照组（62例）和β阻滞剂治疗组（60例），比较两组患者的心功能指标、自主神经功能指标和预后情况。

首先，相对于对照组，β受体阻滞剂治疗组患者的不良事件发生率和病死率均有所降低，但差异均无统计学意义（33.3% vs. 37.1%、6.7% vs. 8.1%；χ² = 0.189、0.087，P均> 0.05）。治疗28 d时，β阻滞剂治疗组患者的左心室射血分数（LVEF）和窦性心搏R-R间期标准差（SDNN）明显高于对照组，而低频段（LF）/高频段（HF）显著低于对照组，差异均有统计学意义[（53 ± 7）% vs.（49 ± 7）%、（186 ± 49）ms vs.（156 ± 53）ms、（1.2 ± 0.5）vs.（2.1 ± 1.0）；t = 3.440、3.103、5.769，P均< 0.05]。

对于AMI介入治疗患者早期应用β受体阻滞剂（美托洛尔），并根据血浆B型尿钠肽（BNP）水平和病情变化适当调整剂量，能更为有效地促进患者心功能恢复，并促使交感神经活性/迷走神经活性的比值趋于正常水平，可能有助于改善患者的预后。

To investigate the effect of early application of β-blocker on cardiac and autonomic nervous functions of the acute myocardial infarction (AMI) patients with interventional treatment.

According to the β-blocker (metoprolol) usage, 122 AMI patients with interventional treatment were divided into the control group (62 cases) and β-blocker treatment group (60 cases).

Compared with the control group, the adverse event and case fatality rates in the β-blocker treatment group were both lower, but had no significant differences (33.3% vs. 37.1%, 6.7% vs. 8.1%; χ² = 0.189, 0.087, all P > 0.05). After a 28-d treatment, the left ventricular ejection fraction (LVEF) and standard diviation of NN intervals (SDNN) in the β-blocker treatment group were much higher than that in the control group, while the low frequency (LF)/high frequency (HF) was much lower than control group [(53 ± 7)% vs. (49 ± 7)%, (186 ± 49) ms vs. (156 ± 53) ms, (1.2 ± 0.5) vs. (2.1 ± 1.0); t = 3.440, 3.103, 5.769, all P < 0.05].

For the AMI patients with interventional treatment, early application of β-blocker (metoprolol) and adjustment of its usage based on the concentration of plasma B-type natriuretic peptide (BNP) and state of the illness changes could effectively promote the cardiac function recovery of AMI patients, also prompt the sympathetic nervous activity/vagus nerve activity ratio returns to the normal level, thus it may help to improve the prognosis of AMI patients.