Ades P A, Thomas J D, Hanson J S, Shapiro S M, LaMountain J
Division of Cardiology, University of Vermont College of Medicine, Burlington 05401.
Am J Cardiol. 1987 Nov 1;60(13):963-6. doi: 10.1016/0002-9149(87)90333-x.
To determine the effect of beta-adrenergic blockade on the submaximal stress test after acute myocardial infarction (AMI), 36 post-AMI patients performed their treadmill test on 2 separate days, with and without metoprolol, in a double-blind, placebo-controlled, crossover design study. Rest and peak submaximal exercise heart rate was diminished by 100 mg of metoprolol administered twice daily (from 84 +/- 3 to 68 +/- 2 beats/min, p less than 0.001, and from 126 +/- 3 to 97 +/- 2 beats/min, p less than 0.001, respectively) compared with placebo. Rest and peak submaximal systolic blood pressure was also decreased (from 121 +/- 3 to 108 +/- 2 mm Hg, p less than 0.001, and from 151 +/- 4 to 124 +/- 3 mm Hg, p less than 0.001). Exercise-induced ST-segment depression of 1 mm or more from baseline occurred in 12 patients taking placebo. However, only 4 of these patients had ST depression when they exercised while taking metoprolol (p less than 0.05). Angina pectoris occurred in 4 patients taking placebo but in only 1 of these taking a beta-blocking drug. It is concluded that beta-blocking therapy renders the post-AMI submaximal stress test less sensitive for markers of exercise-induced ischemia than if the test is performed without the drug. Therefore, when using the prognostic information of published studies, it is important to define the conditions surrounding the exercise test.
为了确定β-肾上腺素能阻滞剂对急性心肌梗死（AMI）后次极量运动试验的影响，36例AMI后患者在一项双盲、安慰剂对照、交叉设计研究中，于2个不同日期分别在服用和未服用美托洛尔的情况下进行了跑步机试验。与安慰剂相比，每日两次服用100 mg美托洛尔可使静息和次极量运动高峰心率降低（分别从84±3次/分钟降至68±2次/分钟，p<0.001；从126±3次/分钟降至97±2次/分钟，p<0.001）。静息和次极量运动高峰收缩压也有所降低（从121±3 mmHg降至108±2 mmHg，p<0.001；从151±4 mmHg降至124±3 mmHg，p<0.001）。服用安慰剂的12例患者运动诱发ST段压低较基线水平≥1 mm。然而，服用美托洛尔进行运动时，这些患者中只有4例出现ST段压低（p<0.05）。服用安慰剂的4例患者出现心绞痛，而服用β受体阻滞剂的患者中只有1例出现心绞痛。结论是，与未服用药物进行试验相比，β受体阻滞剂治疗使AMI后次极量运动试验对运动诱发缺血标志物的敏感性降低。因此，在使用已发表研究的预后信息时，明确运动试验的相关条件很重要。
