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The effects of dexmedetomidine on cardiac electrophysiology in children

Gregory B Hammer1, David R Drover, Hong Cao

  • 1Department of Anesthesiology, Lucile Packard Children's Hospital and Stanford University School of Medicine, Stanford, California, USA. ham@stanford.edu

Anesthesia and Analgesia
|January 1, 2008
PubMed

Insights

Dexmedetomidine (DEX) depresses cardiac conduction in children, affecting heart rate and blood pressure. Its use during pediatric electrophysiology studies may pose risks for bradycardia and AV block.

Area of Science:

  • Pediatric Cardiology
  • Clinical Anesthesiology
  • Pharmacology

Background:

  • Dexmedetomidine (DEX) is an alpha2-adrenergic agonist approved for short-term adult sedation.
  • DEX use in pediatric sedation and anesthesia is increasing, despite lack of FDA approval for this age group.
  • Concerns exist regarding DEX's hemodynamic effects, with no data on its impact on pediatric cardiac conduction.

Purpose of the Study:

  • To characterize the effects of dexmedetomidine on cardiac conduction in pediatric patients.
  • To evaluate hemodynamic and electrophysiologic changes during DEX administration in children.

Main Methods:

  • Twelve pediatric patients (5-17 years) undergoing electrophysiology study received DEX (1 microg/kg IV followed by 0.7 microg x kg(-1) x h(-1) infusion).
  • Hemodynamic variables (heart rate, blood pressure) and cardiac electrophysiologic variables were measured before and during DEX administration.

Main Results:

  • Dexmedetomidine administration led to a significant decrease in heart rate and a significant increase in arterial blood pressure.
  • Sinus node function was significantly affected, indicated by increased sinus cycle length and sinus node recovery time.
  • Atrioventricular nodal function was depressed, evidenced by prolonged Wenckeback cycle length and PR interval.

Conclusions:

  • Dexmedetomidine significantly depresses sinus and atrioventricular nodal function in pediatric patients.
  • The observed hemodynamic changes (bradycardia, hypertension) and conduction system effects suggest DEX may not be ideal for pediatric electrophysiology studies.
  • Caution is advised when using DEX in pediatric patients at risk for bradycardia or atrioventricular nodal block.
Abstract

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