title: Arrhythmias in patients receiving enzyme replacement therapy for infantile Pompe disease.
abstract: OBJECTIVE
  Enzyme replacement therapy in infants with Pompe disease prolongs survival, decreases cardiomegaly, and improves muscle function. Because ectopy has been previously described in these patients, we sought to determine the prevalence and types of arrhythmias.
  
  
  METHODS
  Thirty-eight children with infantile Pompe disease received enzyme replacement therapy in two open-label, multicenter, international, clinical trials. Data were reviewed on a retrospective basis. The corrected QT interval, ejection fraction, and indexed left ventricular mass were measured on a scheduled basis from electrocardiograms and echocardiograms. Arrhythmias were identified and characterized from electrocardiograms, ambulatory electrocardiograms, and point-of-care monitoring. Electrocardiogram and echocardiogram measurements were compared in children with and without arrhythmias.
  
  
  RESULTS
  Seven children (18%) experienced arrhythmias. The QT interval, ejection fraction, indexed left ventricular mass, and rate of reduction of indexed left ventricular mass were not statistically different in those seven versus the other 31 children. Two children with life-threatening arrhythmias had among the highest combined baseline maximum indexed left ventricular mass and QT interval. Their arrhythmias occurred during severe metabolic stress from noncardiac illness.
  
  
  CONCLUSIONS
  There was a high incidence of arrhythmias in our cohort. The relationship of arrhythmias with enzyme replacement therapy, myocardial fibrosis, or simply longer survival is unknown. Therefore, further characterization of specific arrhythmia risk factors and continued vigilance regarding screening for arrhythmias in children receiving enzyme replacement therapy is warranted.
authors.affiliation: Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: Roddy
authors.initials: R
authors.lastname: McDowell
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Li
authors.forename: Daniel Kelly
authors.initials: DK
authors.lastname: Benjamin
authors.forename: Claire
authors.initials: C
authors.lastname: Morgan
authors.forename: Alison
authors.initials: A
authors.lastname: Becker
authors.forename: Priya S
authors.initials: PS
authors.lastname: Kishnani
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Kanter
mesh_terms: D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology*; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D006009:Glycogen Storage Disease Type II / Q000150:complications* / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D008297:Male; D011994:Recombinant Proteins / Q000627:therapeutic use*; D012307:Risk Factors; D016896:Treatment Outcome; D000520:alpha-Glucosidases / Q000627:therapeutic use*
chemical_list: D011994:Recombinant Proteins; C509951:GAA protein, human; D000520:alpha-Glucosidases