Crawford M H
University of Texas Health Science Center, Department of Medicine/Cardiology, San Antonio 78284-7872.
Circulation. 1989 Dec;80(6 Suppl):IV74-7.
Asymptomatic myocardial ischemia likely results from an imbalance between myocardial oxygen supply and demand. Although changes in coronary vasomotor tone probably are important in the genesis of asymptomatic ischemia, heart rate increases also play a critical role. Consequently, all three classes of antianginal agents, nitrates, beta-blockers, and calcium entry blockers, have been shown efficacious as monotherapy for silent ischemia. Comparative studies have demonstrated that agents or combination therapies that control heart rate increases during normal activities are superior to regimens that increase average heart rate. Consideration of the side-effect profile of any therapy for asymptomatic patients also is important. The ideal therapy would be with one drug that reduced coronary vasomotor tone and myocardial oxygen demand during normal activities and had no adverse effects. Currently, the calcium entry blockers, diltiazem and verapamil, most closely approximate this ideal. It has yet to be proven, however, that the treatment of asymptomatic myocardial ischemia improves the prognosis of patients with coronary artery disease, and the risk-benefit ratio of pharmacological therapy is not established.
无症状性心肌缺血可能是心肌氧供与需求失衡所致。尽管冠状动脉血管舒缩张力的变化在无症状性缺血的发生中可能很重要，但心率增加也起着关键作用。因此，所有三类抗心绞痛药物，即硝酸盐类、β受体阻滞剂和钙通道阻滞剂，已被证明作为无症状性缺血的单一疗法是有效的。比较研究表明，在正常活动期间控制心率增加的药物或联合疗法优于增加平均心率的治疗方案。考虑任何针对无症状患者的治疗的副作用也很重要。理想的治疗方法是使用一种药物，该药物能在正常活动期间降低冠状动脉血管舒缩张力和心肌氧需求，且无不良反应。目前，钙通道阻滞剂地尔硫䓬和维拉帕米最接近这一理想状态。然而，无症状性心肌缺血的治疗是否能改善冠心病患者的预后尚未得到证实，药物治疗的风险效益比也未确立。
