title: Handheld ECG in analysis of arrhythmia and heart rate variability in children with Fontan circulation.
abstract: BACKGROUND
  Our aim was to evaluate the intermittent use of a handheld ECG system for detecting silent arrhythmias and cardiac autonomic dysfunction in children with univentricular hearts.
  
  
  METHODS
  Twenty-seven patients performed intermittent ECG recordings with handheld devices during a 14-day period. A manual arrhythmia analysis was performed. We analyzed heart rate variability (HRV) using scatter plots of all interbeat intervals (Poincaré plots) from the total observation period. Reference values of HRV indices were determined from Holter-ECGs in 41 healthy children.
  
  
  RESULTS
  One asymptomatic patient had frequent ventricular extra systoles. Another patient had episodes with supraventricular tachycardia (with concomitant palpitations). Seven patients showed reduced HRV.
  
  
  CONCLUSIONS
  Asymptomatic arrhythmia was detected in one patient. The proposed method for pooling of intermittent recordings from handheld or similar devices may be used for detection of arrhythmias as well as for cardiac autonomic dysfunction.
authors.affiliation: Department of Clinical Sciences, Umeå University, Sweden. Electronic address: jenny.alenius@pediatri.umu.se.
authors.forename: Jenny Alenius
authors.initials: JA
authors.lastname: Dahlqvist
authors.affiliation: Department of Radiation Sciences, Biomedical Engineering, Umeå University, Sweden.
authors.forename: Marcus
authors.initials: M
authors.lastname: Karlsson
authors.affiliation: Department of Radiation Sciences, Biomedical Engineering, Umeå University, Sweden.
authors.forename: Urban
authors.initials: U
authors.lastname: Wiklund
authors.affiliation: Clinical Physiology, Heart Centre and Department of Surgical and Perioperative Sciences, Umeå University, Sweden.
authors.forename: Rolf
authors.initials: R
authors.lastname: Hörnsten
authors.affiliation: Department of Clinical Sciences, Umeå University, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Rydberg
mesh_terms: D000293:Adolescent; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008904:Miniaturization; D019095:Point-of-Care Systems; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Arrhythmia; Fontan circulation; Handheld ECG; Heart rate variability