Malik M, Farrell T, Camm A J
Department of Cardiological Sciences, St. George's Hospital Medical School, London, England.
Am J Cardiol. 1990 Nov 1;66(15):1049-54. doi: 10.1016/0002-9149(90)90503-s.
This study examined heart rate (HR) variability in patients surviving acute myocardial infarction (AMI) to find the optimum time and duration of recording of the ambulatory electrocardiogram for the prediction of the risk of sudden cardiac death, or serious arrhythmic events, or both. Twenty patients (group I) who initially survived an AMI but later experienced serious events (death or symptomatic sustained ventricular tachycardia) during a 6-month follow-up were compared with 20 patients (group II) who remained free of complications for greater than 6 months after discharge. Groups I and II were matched with regard to age, gender, infarct site, ejection fraction, and beta-blocker treatment. HR variability was assessed in the 24-hour electrocardiograms recorded during the first 2 weeks after an AMI and in various portions of the complete 24-hour recording, with both the beginning and the length of the analyzed portion varied by 20 minutes (a total of 5,113 possibilities). The maximum reduction of HR variability in group I patients was systematically found when assessing HR variability in recordings starting approximately at 6 A.M. and lasting for approximately 8 hours. In the low-risk patient, the diurnal rhythm of HR variability is more marked than in the high-risk patient and the long-term components of HR variability due to the diurnal variation must be included in the measurement of HR variability when using it as a long-term predictor of risk from arrhythmic events after an AMI.
本研究检测了急性心肌梗死（AMI）存活患者的心率（HR）变异性，以确定动态心电图记录的最佳时间和时长，用于预测心源性猝死风险、严重心律失常事件风险或两者。将20例患者（第一组）与20例患者（第二组）进行比较，第一组患者最初在急性心肌梗死后存活，但在6个月随访期间发生了严重事件（死亡或症状性持续性室性心动过速），第二组患者出院后6个月以上无并发症。第一组和第二组在年龄、性别、梗死部位、射血分数和β受体阻滞剂治疗方面相匹配。在急性心肌梗死后前2周记录的24小时心电图以及完整24小时记录的不同部分评估心率变异性，分析部分的起始时间和时长均以20分钟为单位变化（共有5113种可能性）。当评估大约上午6点开始并持续约8小时的记录中的心率变异性时，系统地发现第一组患者心率变异性的最大降低。在低风险患者中，心率变异性的昼夜节律比高风险患者更明显，在将心率变异性用作急性心肌梗死后心律失常事件风险的长期预测指标时，由于昼夜变化导致的心率变异性长期成分必须纳入心率变异性测量中。
