COMPONENTS OF HEART-RATE VARIABILITY MEASURED DURING HEALING OF ACUTE MYOCARDIAL-INFARCTION
COMPONENTS OF HEART-RATE VARIABILITY MEASURED DURING HEALING OF ACUTE MYOCARDIAL-INFARCTION
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DOI：
10.1016/0002-9149(88)90917-4
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发表时间：
1988-02-01
影响因子：
2.8
通讯作者：
MILLER, JP
中科院分区：
文献类型：
--
作者：
BIGGER, JT;KLEIGER, RE;MILLER, JP
在心脏正常的人中发现高度的心率（HR）变异性，而在患有严重冠状动脉疾病、充血性心力衰竭和糖尿病神经病变的患者中可以发现低HR变异性。急性心肌梗死后两周，即使调整了临床风险指标、左心室射血分数、HR和室性心律失常，低HR变异性预测长期生存期降低。本研究阐明了低和高HR变异性患者之间HR和HR变异性差异的原因。在配对研究中，随机选择了10名HR变异性低（24小时N-N间期标准差< 50 ms）的患者。对于这10名患者中的每一名，具有HR变异性（N-N间期的24小时标准差≥ 1.0%）的对照患者被随机分为两组。100 ms），年龄、左心室射血分数和罗音相匹配。服用洋地黄或β-肾上腺素的患者排除肾上腺素能阻滞药。24小时心电图的分析显示，与高HR变异性组相比，低HR变异性组：（1）白天和夜间平均HR更快;（2）白天和夜间HR之间的差异更小;（3）连续N-N间期之间的差异> 50 ms的比例更小;以及（4）每天HR“尖峰”的数量（HR增加≥ 50 ms）更小。这些发现表明，与对照组患者相比，低HR变异性患者的副交感神经活动显著减少。高交感神经活性的低副交感神经活性降低了心室颤动的电阈值，增加了心肌缺血时心室颤动的概率，并可能解释了急性心肌梗死后低HR变异性与死亡率之间的关系。
A high degree of heart rate (HR) variability is found in persons with normal hearts, whereas low HR variability can be found in patients with severe coronary artery disease, congestive heart failure and diabetic neuropathy. Two weeks after acute myocardial infarction, low HR variability predicted reduced long-term survival term survival even after adjusting for clinical risk indicators, left ventricular ejection fraction, HR and ventricular arrhythmias. The present study elucidated the causes of differences in HR and HR variability between patients with low and high HR variability. In a matched-pair study, 10 patients with low HR variability (24-hour standard deviation of N-N intervals < 50 ms) were randomly selected. For each of these 10 patients, a control patient with HR variability (24-hour standard deviation of N-N intervals .gtoreq. 100 ms), matched for age, left ventricular ejection fraction and rales in the coronary care unit was selected. Patients who were taking either digitalis or .beta.-adrenergic blocking drugs were excluded. Analysis of 24-hour electrocardiograms showed that for the low HR variability group compared with the high: (1) the daytime and nighttime average HR was faster; (2) the difference between daytime and nighttime HR was less; (3) the proportion of differences > 50 ms between successive N-N intervals was smaller; and (4) the number of HR "spikes" per day (increase in HR .gtoreq. 10 beats/min, lasting from 3 to 15 minutes) was less. These findings indicate that parasympathetic nervous activity is substantially reduced in patients with low HR variability compared with control patients. Low parasympathetic activity of high sympathetic activity decreases the electrical ventricular fibrillation threshold and increases the probability of ventricular fibrillation during myocardial ischemica, and may explain the association between low HR variability and mortality after acute myocardial infarction.