Bugiardini R, Borghi A, Biagetti L, Puddu P
Institute of Patologia Medica, University of Bologna, Italy.
Am J Cardiol. 1989 Feb 1;63(5):286-90. doi: 10.1016/0002-9149(89)90332-9.
The effects of oral verapamil, 320 mg daily, propranolol, 120 to 160 mg daily, and placebo were compared in 16 patients presenting with transient myocardial ischemia without evidence of coronary atherosclerosis or vasospasm on angiography (syndrome X). Testing was done according to a randomized double-blind crossover placebo-controlled trial consisting of 3 consecutive 7-day treatment periods with verapamil or propranolol or placebo. Patients underwent continuous 48-hour electrocardiographic monitoring before therapy (run-in phase) and during the last 2 days of each treatment period. A total of 391 episodes of diagnostic (greater than or equal to 0.15 mV) ST depression was recorded during the trial. Of these, 23 were symptomatic. None of the episodes occurred while the patients were asleep, 25% during exercise, 35% during minimal physical activity and 40% at rest. Rest included activities demanding mental arousal (conversation, reading or watching television). Heart rate at the onset of ST depression was higher (greater than or equal to 10 beats/min) than that observed in the 5 minutes preceding ischemia in 95% of the episodes. In the group as a whole, the average number of ischemic episodes per 24 hours was significantly reduced during propranolol therapy compared with placebo (0.7 +/- 0.6 vs 3.9 +/- 1.8; p less than 0.0005). No significant differences were seen during verapamil treatment (3.4 +/- 1.7 vs 3.9 +/- 1.8). It is concluded that transient myocardial ischemia in syndrome X is mostly precipitated by an increase in oxygen consumption, presumably due to a heightened sympathetic activity. Accordingly, beta blockers may represent the first line of treatment.
对16例出现短暂性心肌缺血但血管造影无冠状动脉粥样硬化或血管痉挛证据（X综合征）的患者，比较了每日口服320毫克维拉帕米、每日口服120至160毫克普萘洛尔和安慰剂的效果。试验按照随机双盲交叉安慰剂对照试验进行，包括连续3个7天的治疗期，分别使用维拉帕米、普萘洛尔或安慰剂。患者在治疗前（导入期）以及每个治疗期的最后2天接受连续48小时的心电图监测。试验期间共记录到391次诊断性（≥0.15毫伏）ST段压低发作。其中23次有症状。这些发作均未在患者睡眠时发生，25%发生在运动期间，35%发生在轻度体力活动期间，40%发生在休息时。休息包括需要精神兴奋的活动（交谈、阅读或看电视）。在95%的发作中，ST段压低开始时的心率高于缺血前5分钟观察到的心率（≥10次/分钟）。与安慰剂相比，在整个组中，普萘洛尔治疗期间每24小时缺血发作的平均次数显著减少（0.7±0.6对3.9±1.8；p<0.0005）。维拉帕米治疗期间未观察到显著差异（3.4±1.7对3.9±1.8）。结论是，X综合征中的短暂性心肌缺血大多由耗氧量增加引起，推测是由于交感神经活动增强。因此，β受体阻滞剂可能代表一线治疗方法。
