Hohnloser S H, Klingenheben T
J. W. Goethe Universität, Med. Klinik IV, Kardiologie & Nephrologie, Frankfurt.
Z Kardiol. 1996;85 Suppl 6:35-43.
The autonomic nervous system plays a decisive role in the genesis of sudden cardiac death. During recent years, two noninvasive tests for quantitative assessment of cardiac autonomic tone have become available: analysis of heart rate variability from 24-h ambulatory recordings and determination of baroreflex-sensitivity by means of the phenylephrine method. Numerous experimental and clinical studies suggest that heart rate variability assesses tonic vagal activity whereas baroreflex-sensitivity is considered to reflect phasic or reflex vagal activity. Both methods, however, are not redundant but rather complimentary. An advantage of assessment of baroreflex-sensitivity is represented by the fact that it can be performed under controlled laboratory conditions which yields a good intra- and interindividual comparability of test results. Some retrospective as well as prospective studies have assessed the value of determination of cardiac autonomic tone with respect to risk stratification after myocardial infarction. In general, these studies indicate that the combined assessment of autonomic tone together with left ventricular function yields an improved prediction particularly of the risk of dying due to arrhythmic events. It appears that baroreflex-sensitivity is particularly useful to predict arrhythmic events whereas heart rate variability seems to be linked more to cardiovascular mortality. Preliminary results of the largest prospective study of this kind, the ATRAMI study, indicate that the combined assessment of LVEF and baroreflex-sensitivity considerably improve risk stratification after myocardial infarction. If the final analysis of this trial confirms this, prospective interventional studies should be initiated to evaluate our ability of reducing the risk of sudden death based on noninvasive risk stratification.
自主神经系统在心脏性猝死的发生过程中起决定性作用。近年来，出现了两种用于定量评估心脏自主神经张力的非侵入性检测方法：通过24小时动态记录分析心率变异性，以及采用去氧肾上腺素法测定压力反射敏感性。大量实验和临床研究表明，心率变异性评估的是迷走神经的紧张性活动，而压力反射敏感性被认为反映的是阶段性或反射性迷走神经活动。然而，这两种方法并非多余，而是相辅相成的。评估压力反射敏感性的一个优点是，它可以在可控的实验室条件下进行，从而使检测结果在个体内和个体间具有良好的可比性。一些回顾性和前瞻性研究评估了测定心脏自主神经张力在心肌梗死后风险分层方面的价值。总体而言，这些研究表明，自主神经张力与左心室功能的联合评估能更好地预测风险，尤其是心律失常事件导致的死亡风险。似乎压力反射敏感性对预测心律失常事件特别有用，而心率变异性似乎与心血管死亡率的关联更大。此类最大规模的前瞻性研究——ATRAMI研究的初步结果表明，左心室射血分数（LVEF）和压力反射敏感性的联合评估可显著改善心肌梗死后的风险分层。如果该试验的最终分析证实了这一点，就应该启动前瞻性干预研究，以评估我们基于非侵入性风险分层降低猝死风险的能力。
