Palix Julie, Akselrod Michel, Cungi Charly, Giuliani Fabienne, Favrod Jérôme
School of Nursing Sciences, La Source, University of Applied Sciences and Arts of Western Switzerland, Lausanne, Switzerland; Department of Psychiatry, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
Ecole Polytechnique Fédérale de Lausanne , Lausanne , Switzerland.
Front Psychiatry. 2017 Feb 1;8:4. doi: 10.3389/fpsyt.2017.00004. eCollection 2017.
The present study investigates the possibilities of using heart rate variability (HRV) parameters as physiological markers that precede increase in observed behavioral excitation of intellectually disabled individuals. The ability to recognize or predict such patterns, especially in patients showing unpredictable reactions and language deficiencies, might be a major step forward in clinical research.
Thirteen volunteers with intellectual disabilities, who had suffered of at least one event of overt aggression in the preceding 3 months, participated to the study. The protocol consists in the acquisition of continuous electrocardiogram (ECG) throughout approximately two times of 8 h in natural situation, using a T-shirt integrated with sensors. Simultaneously, an observer evaluates the patient's level of overt excitation from calm (level 1) to extremely tense (level 5) and send online Bluetooth these triggers into the ECG signals. The HRV indexes were then estimated offline on the basis of the inter-beat intervals recorded by the ECG, independently for the 30 min preceding each behavioral tension marking point, averaged, and compared through non-parametric Wilcoxon matched-pairs test. Of these, the RMSSD and LF/HF calculations were used to observe the fluctuations of inhibitory activity and cardiovagal balance through different tension states.
Seven individuals have sufficient reliable data for analysis. They have reached at least a level 3 of behavioral excitation (moderately tense) or more (very to extremely tense, level 4 and 5) and have been retained for further analysis. In sum, a total of 197 periods of tension were kept, made up of 46 periods of slight excitation (level 2), 18 of moderate excitation (level 3), 10 of high excitation (level 4), and 5 of extreme agitation (level 5). Variations in the HRV as a function of degree of excitation are observed for RMSSD index only (inhibitory parasympathetic activity). The changes from calm to increasing levels of excitation are characterized by a significant downfall in RMSSD index when patients were evaluated to be in a very high level of tension (level 4).
The presence of precursors to agitation, reflected in the falling-off of parasympathetic activity, offers potentially interesting prospects for therapeutic development.
本研究探讨了将心率变异性（HRV）参数用作生理标志物的可能性，这些标志物先于智力残疾个体观察到的行为兴奋增加。识别或预测此类模式的能力，尤其是在表现出不可预测反应和语言缺陷的患者中，可能是临床研究向前迈出的重要一步。
13名智力残疾志愿者参与了该研究，他们在过去3个月中至少发生过一次明显的攻击行为。该方案包括在自然情况下使用集成传感器的T恤衫连续采集约两个8小时的心电图（ECG）。同时，一名观察者评估患者从平静（1级）到极度紧张（5级）的明显兴奋程度，并通过蓝牙将这些触发信号在线发送到ECG信号中。然后根据ECG记录的心跳间期离线估计HRV指数，在每个行为紧张标记点之前的30分钟独立进行，求平均值，并通过非参数Wilcoxon配对检验进行比较。其中，RMSSD和LF/HF计算用于观察不同紧张状态下抑制活动和心脏迷走神经平衡的波动。
7名个体有足够可靠的数据进行分析。他们的行为兴奋程度至少达到3级（中度紧张）或更高（非常紧张至极度紧张，4级和5级），并被保留用于进一步分析。总之，共保留了197个紧张期，包括46个轻度兴奋期（2级）、18个中度兴奋期（3级）、10个高度兴奋期（4级）和5个极度激动期（5级）。仅观察到RMSSD指数（抑制性副交感神经活动）的HRV随兴奋程度的变化。当患者被评估处于非常高的紧张水平（4级）时，从平静到兴奋程度增加的变化特征是RMSSD指数显著下降。
副交感神经活动下降反映出的激动前驱现象，为治疗发展提供了潜在的有趣前景。
