Morikami Y, Yasue H
Division of Cardiology, Kumamoto University Medical School, Kumamoto City, Japan.
Am J Cardiol. 1991 Sep 1;68(6):580-4. doi: 10.1016/0002-9149(91)90347-n.
To evaluate the efficacy of slow-release nifedipine (a single dose of 20 mg given at 10 P.M. or 2 doses of 20 mg at 10 P.M. and 6 A.M.) on ischemic episodes in patients with variant angina, a single-blind crossover study with ambulatory electrocardiographic monitoring was performed in 15 patients (13 men and 2 women, mean age 63 years). In all, there were 646 ischemic episodes detected with ambulatory electrocardiographic monitoring during the study period, and 618 episodes of them occurred during placebo periods with a circadian variation. Sixty-nine percent of the episodes in placebo periods were asymptomatic. The number of anginal attacks, nitroglycerin tablets taken, ST-segment elevation and the total ischemic duration significantly decreased during nifedipine therapy compared with results after the placebo therapy period, respectively (p less than 0.01 or 0.05). Twenty-eight ischemic episodes occurred during nifedipine therapy when the plasma level of nifedipine was low. Thus, asymptomatic ischemic episodes more frequently occur than symptomatic episodes and the administration of slow-release nifedipine is highly effective in suppressing not only symptomatic but also asymptomatic myocardial ischemia in patients with variant angina. The timing of the administration of slow-release nifedipine is an important factor in suppressing ischemic episodes.
为评估缓释硝苯地平（晚上10点单次服用20毫克或晚上10点和早上6点各服用20毫克）对变异型心绞痛患者缺血发作的疗效，对15例患者（13例男性和2例女性，平均年龄63岁）进行了一项采用动态心电图监测的单盲交叉研究。在研究期间，通过动态心电图监测共检测到646次缺血发作，其中618次发作发生在安慰剂期，且存在昼夜变化。安慰剂期69%的发作无症状。与安慰剂治疗期后的结果相比，硝苯地平治疗期间心绞痛发作次数、硝酸甘油片服用量、ST段抬高及总缺血持续时间均显著减少（p<0.01或0.05）。硝苯地平治疗期间，当血浆硝苯地平水平较低时发生了28次缺血发作。因此，无症状缺血发作比有症状发作更频繁，且缓释硝苯地平给药不仅对变异型心绞痛患者的有症状心肌缺血，而且对无症状心肌缺血均有高度疗效。缓释硝苯地平的给药时间是抑制缺血发作的一个重要因素。
