Buchhorn Reiner, Conzelmann Annette, Willaschek Christian, Störk Dagmar, Taurines Regina, Renner Tobias J
Department of Paediatrics, Caritas Krankenhaus, Bad Mergentheim, Germany.
Atten Defic Hyperact Disord. 2012 Jun;4(2):85-91. doi: 10.1007/s12402-012-0072-8. Epub 2012 Feb 11.
Although an extensive number of studies support the efficacy and tolerability of stimulants in the treatment of attention deficit/hyperactivity disorder (ADHD), in recent years, increasing concerns have been raised about their cardiovascular safety. We investigated whether a time domain analysis of heart rate variability (HRV) recordings in 24-h ECG under medication with stimulants yielded new information about therapy control in ADHD. We analysed the HRV parameter standard deviation of all normal sinus RR intervals over 24 h (SDNN), percentage of successive normal sinus RR intervals > 50 ms (pNN50) and root-mean-square of the successive normal sinus RR interval difference (rMSSD) from 23 children diagnosed by ADHD (19 boys and 4 girls), aged 10.5 ± 2.2 years, who were consecutively referred to our outpatient clinic for paediatric cardiology. Eleven children received medication with methylphenidate (MPH), while twelve children were initially examined without medication. Of these, eight probands were re-examined after therapy with MPH was established. Controls comprised 19 children (10 boys, 9 girls) from our Holter ECG data base without any cardiac or circulatory disease. Compared to healthy controls, the ADHD children with and without MPH treatment showed significantly higher mean heart rates (ADHD without MPH: 94.3 ± 2.2; ADHD with MPH: 90.5 ± 1.8, controls: 84.7 ± 1.8). pNN50 (ADHD without MPH: 6.5 ± 2.7; ADHD with MPH: 14.2 ± 6.9, controls: 21.5 ± 9.0) and rMSSD (ADHD without MPH: 26.1 ± 4.1; ADHD with MPH: 36.7 ± 8.3, controls: 44.5 ± 10.1) were lowest in ADHD children without MPH, middle in ADHD children with MPH and highest in controls. SDNN values were not significantly different. The hourly analysis shows highly significant reduced pNN50 and rMSSD values in untreated ADHD children between 5:00 pm and 6:00 am while the pattern approaches to levels of controls during MPH treatment. Data of this pilot study indicate a decreased vagal tone with significantly diminished HRV and higher heart rates in unmedicated ADHD children. These parameters of autonomic activation are ameliorated by MPH treatment. No evidence for negative impact of MPH on HRV was detected. Further studies will clarify a potential cardio-protective effect of MPH in ADHD.
尽管大量研究支持兴奋剂在治疗注意力缺陷/多动障碍（ADHD）方面的疗效和耐受性，但近年来，人们对其心血管安全性的担忧日益增加。我们调查了在使用兴奋剂药物治疗期间，对24小时心电图中的心率变异性（HRV）记录进行时域分析是否能得出有关ADHD治疗控制的新信息。我们分析了23名被诊断为ADHD的儿童（19名男孩和4名女孩）的HRV参数，即24小时内所有正常窦性RR间期的标准差（SDNN）、连续正常窦性RR间期>50毫秒的百分比（pNN50）以及连续正常窦性RR间期差值的均方根（rMSSD），这些儿童年龄为10.5±2.2岁，他们是连续被转诊到我们儿科心脏病门诊的。11名儿童接受了哌甲酯（MPH）药物治疗，而12名儿童最初未用药进行检查。其中，8名受试者在确立MPH治疗后再次接受检查。对照组包括19名来自我们动态心电图数据库的儿童（10名男孩，9名女孩），他们没有任何心脏或循环系统疾病。与健康对照组相比，接受和未接受MPH治疗的ADHD儿童的平均心率显著更高（未接受MPH治疗的ADHD儿童：94.3±2.2；接受MPH治疗的ADHD儿童：90.5±1.8，对照组：84.7±1.8）。pNN50（未接受MPH治疗的ADHD儿童：6.5±2.7；接受MPH治疗的ADHD儿童：14.2±6.9，对照组：21.5±9.0）和rMSSD（未接受MPH治疗的ADHD儿童：26.1±4.1；接受MPH治疗的ADHD儿童：36.7±8.3，对照组：44.5±10.1）在未接受MPH治疗的ADHD儿童中最低，在接受MPH治疗的ADHD儿童中处于中间水平，在对照组中最高。SDNN值无显著差异。每小时分析显示，未经治疗的ADHD儿童在下午5点至早上6点之间pNN50和rMSSD值显著降低，而在MPH治疗期间该模式接近对照组水平。这项初步研究的数据表明，未用药的ADHD儿童迷走神经张力降低，HRV显著减弱且心率较高。MPH治疗可改善这些自主神经激活参数。未检测到MPH对HRV有负面影响的证据。进一步的研究将阐明MPH在ADHD中潜在的心脏保护作用。
