title: Electrocardiographic and electrophysiologic effects of dexmedetomidine on children.
abstract: BACKGROUND
  Dexmedetomidine (DEX) is a highly selective alpha-2-adrenergic agonist approved for short-term sedation and monitored anesthesia care in adults. Its effects on the electrocardiography and cardiac conduction tissue are not well described in the literature. Therefore, we aimed to characterize the electrocardiographic and electrophysiologic effects of DEX in children.
  
  
  METHODS
  Twenty children (11 boys and nine girls) between the ages of eight and 17 undergoing electrophysiology study and ablation of the supraventricular tachycardia had hemodynamic and cardiac electrophysiologic variables measured before and during the administration of DEX (1 microgram/kg IV over 10 minutes followed by a 10-minute continuous infusion of 0.5 microgram/kg/h).
  
  
  RESULTS
  A significant decrease in heart rate was seen after the administration of DEX, but the systolic-diastolic-mean arterial pressure, respiratory rate, and end-tidal carbon dioxide did not change. Corrected sinus node recovery times and baseline sinus cycle lengths, which are markers of sinus nodal function, were both lengthened with the administration of DEX. Atrioventricular (AV) nodal function, as evidenced by the Wenckebach cycle length, the ventriculoatrial block cycle length, and AV nodal effective refractory periods, was lengthened significantly. We also found that DEX increased the atrial refractory period and diminished atrial excitability.
  
  
  CONCLUSIONS
  DEX significantly depressed sinus and AV nodal function in pediatric patients without significant electrocardiogram interval changes, other than a trend toward lower heart rates. Although no spontaneous AV nodal block and no clinically significant bradycardia were seen, we recommend that DEX be used with caution in patients at risk for bradycardia and/or AV nodal dysfunction due to its associated comorbidities.
authors.affiliation: Thoracic and Cardiovascular Surgery Center and Research Hospital, Istanbul, Turkey.
authors.forename: Yakup
authors.initials: Y
authors.lastname: Ergul
authors.affiliation: Thoracic and Cardiovascular Surgery Center and Research Hospital, Istanbul, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Unsal
authors.affiliation: Thoracic and Cardiovascular Surgery Center and Research Hospital, Istanbul, Turkey.
authors.forename: Isa
authors.initials: I
authors.lastname: Ozyilmaz
authors.affiliation: Thoracic and Cardiovascular Surgery Center and Research Hospital, Istanbul, Turkey.
authors.forename: Erkut
authors.initials: E
authors.lastname: Ozturk
authors.affiliation: Thoracic and Cardiovascular Surgery Center and Research Hospital, Istanbul, Turkey.
authors.forename: Hayat
authors.initials: H
authors.lastname: Carus
authors.affiliation: Thoracic and Cardiovascular Surgery Center and Research Hospital, Istanbul, Turkey.
authors.forename: Alper
authors.initials: A
authors.lastname: Guzeltas
mesh_terms: D000293:Adolescent; D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology*; D001283:Atrioventricular Node / Q000187:drug effects; D017115:Catheter Ablation; D002648:Child; D020927:Dexmedetomidine / Q000494:pharmacology*; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics; D006801:Humans; D008297:Male; D011446:Prospective Studies; D013617:Tachycardia, Supraventricular / Q000188:drug therapy* / Q000601:surgery
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D020927:Dexmedetomidine
keywords: children; dexmedetomidine; electrocardiography; electrophysiologic variables