HEART RATE VARIABILILTY AND SUDDEN CARDIAC DEATH

心脏性猝死通常是由恶性心室病引起的 心律不齐。冠心病室性心律失常 疾病，是由于基质(疤痕)之间的相互作用 脑室)、触发事件(自发的脑室 心律失常)，以及自主神经系统。非侵入性 需要各种方法来评估这三个风险组成部分 以制定全面的检测和预防计划。 有合理的非侵入性筛查试验 致心律失常底物(左心室射血分数和 信号平均心电图仪)，并用于触发事件 (24小时连续心电记录)。我们认为， 心率或心率变异性可以提供 自主神经系统活动的非侵入性评估。我们 已经发现了一种衡量心脏周期变异性的宽带指标， 连续时间内所有正常R-R间期的标准差 心肌梗死后11天加/减3天24小时心电记录 脑梗塞，预测在接下来的两到四年内死亡 独立于左心功能不全和自发性 室性心律失常。我们建议评估各种不同的 测量心率或周期变异性在时间和 心肌梗死后早期的频域特征 预测死亡的准确性(总死亡、心脏死亡、突发死亡和 心律失常死亡)。我们将比较短期和长期的衡量标准- 足月心率和心率变异性。我们将决定 我们的日常重现性和变化的时间进程 心率变异性和心率变异性的测量 在心肌梗死后晚期测量后续死亡率 和恶性室性心律失常的发展。我们会 对比两组患者术后心率和心率变异性 心肌梗死患者年龄、性别匹配正常 受试者和恶性脑室患者所做的实验 心律不齐。我们将在几个大型项目中进行这些分析 既往心肌梗死患者样本或 恶性室性心律失常与一例正常人 研究对象。我们希望开发新的、改进的非侵入性方法。 用于检测那些最有可能发展为恶性肿瘤的患者 室性心律失常与心脏性猝死 改进对心脏性猝死的检测和预防。

Sudden cardiac death usually is caused by malignant ventricular arrhythmias. Malignant ventricular arrhythmias, in coronary heart disease, are due to an interplay among substrate (scarred ventricles), triggering events (spontaneous ventricular arrhythmias), and the autonomic nervous system. Non-invasive methods are needed to evaluate these three components of risk in order to develop comprehensive detection and prevention programs. There are reasonable non-invasive screening test for the arrhythmogenic substrate (left ventricular ejection fraction and signal averaged electro-cardiograms), and for triggering events (24-hour continuous ECG recordings). We believe that measures of heart rate or heart period variability may provide the means for non-invasive assessment of autonomic nervous system activity. We have found that a broad band measure of heart period variability, the standard deviation of all normal R-R intervals in a continuous 24-hour ECG recording made 11 plus/minus 3 days after myocardial infarction, predicts mortality in the subsequent two to four years independently of left ventricular dysfunction and spontaneous ventricular arrhythmias. We propose to evaluate various measurements of heart rate or period variability in the time and frequency domains made early after myocardial infarction for their accuracy in predicting death (total, cardiac, sudden, and arrhythmic death). We will compare measurements of short and long- term heart rate and heart period variability. We will determine the day-to-day reproducibility and the time course of change of our measures of heart rate variability and heart rate variability measured late after myocardial infarction for subsequent mortality and development of malignant ventricular arrhythmias. We will contrast the heart rate and heart period variability findings after myocardial infarction with those in age and sex matched normal subjects and with those made in patients with malignant ventricular arrhythmias. We will conduct these analyses in several large samples of patients with previous myocardial infarction or malignant ventricular arrhythmias and in a sample of normal subjects. We hope to develop new, improved non-invasive methods for detecting those patients most likely to develop malignant ventricular arrhythmias and sudden cardiac death and point the way to improved detection and prevention of sudden cardiac death.