兒童患有ADHD者常以處方藥Methylphenidate(利他能錠)治療. 此臨床研究(平均 10歲)發現患有ADHD者(不管有無服藥)其心跳較正常者高, 自律神經活性(rMSSD及pNN50)以ADHD無服藥者最低, ADHD有服藥者次之,正常者最高; 臨床資料也顯示ADHD無服藥者其副交感嚴重撤退,而服用Methylphenidate有改善作用.
Heart rate variability and methylphenidate in children with ADHD.
Author(s)Buchhorn R, Conzelmann A, Willaschek C, Störk D, Taurines R, Renner TJ InstitutionDepartment of Paediatrics, Caritas Krankenhaus, Bad Mergentheim, Germany, email@example.com.
Source Atten Defic Hyperact Disord 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.LanguageENGPub Type(s)JOURNAL ARTICLE