Table of Contents
ISRN Pharmacology
Volume 2012, Article ID 170935, 4 pages
http://dx.doi.org/10.5402/2012/170935
Research Article

How to Predict the Impact of Methylphenidate on Cardiovascular Risk in Children with Attention Deficit Disorder: Methylphenidate Improves Autonomic Dysfunction in Children with ADHD

1Department of Paediatrics, Caritas Hospital, 97980 Bad Mergentheim, Germany
2Department of Paediatrics, The University of Western Ontario, London, ON, Canada N6A 5W9
3Department of Pediatric Cardiology, Hannover Medical School, 30625 Hannover, Germany

Received 9 November 2011; Accepted 8 December 2011

Academic Editor: T. B. Vree

Copyright © 2012 Reiner Buchhorn et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Although stimulants have long been touted as treatments for attention deficit disorder with or without hyperactivity (ADHD), in recent years, increasing concerns have been raised about the cardiovascular safety of these medications. We aimed to prove if measurements of autonomic function with time domain analysis of heart rate variability (HRV) in 24-hour Holter ECG are useful to predict the risk of sudden cardiac death in ADHD children and adolescents. Methods. We analysed HRV obtained from children with the diagnosis of ADHD prior to ( 𝑁 = 1 2 ) or during medical therapy ( 𝑁 = 1 9 ) with methylphenidate (MPH), aged 1 0 . 8 ± 2 . 0 years (mean ± SD), who were referred to our outpatient Paediatric Cardiology Clinic to rule out heart defect. As a control group, we compared the HRV data of 19 age-matched healthy children without heart defect. Results. Average HRV parameters from 24-hour ECG in the ADHD children prior to MPH showed significant lower values compared to healthy children with respect to rMSSD ( 2 6 ± 4  ms versus 4 4 ± 1 0  ms, 𝑃 0 . 0 0 0 1 ) and pNN50 ( 6 . 5 ± 2 . 7 % versus 2 1 . 5 ± 9 . 0 % , 𝑃 0 . 0 0 0 1 ). These values improved in MPH-treated children with ADHD (RMSSD: 3 6 ± 8  ms; pNN50: 1 4 . 2 ± 6 . 9 % ). Conclusion. Children who suffer from ADHD show significant changes in HRV that predominantly reflects diminished vagal tone, a well-known risk factor of sudden cardiac death in adults. In our pilot study, MPH treatment improved HRV.