title: Mid-term echocardiographic follow up of left ventricular function with permanent right ventricular pacing in pediatric patients with and without structural heart disease.
abstract: BACKGROUND
  Chronic right ventricular apical pacing may have detrimental effect on left ventricular function and may promote to heart failure in adult patients with left ventricular dysfunction.
  
  
  METHODS
  A group of 99 pediatric patients with previously implanted pacemaker was studied retrospectively. Forty-three patients (21 males) had isolated congenital complete or advanced atrioventricular block. The remaining 56 patients (34 males) had pacing indication in the presence of structural heart disease. Thirty-two of them (21 males) had isolated structural heart disease and the remaining 24 (13 males) had complex congenital heart disease. Patients were followed up for an average of 53 +/- 41.4 months with 12-lead electrocardiogram and transthoracic echocardiography. Left ventricular shortening fraction was used as a marker of ventricular function. QRS duration was assessed using leads V5 or II on standard 12-lead electrocardiogram.
  
  
  RESULTS
  Left ventricular shortening fraction did not change significantly after pacemaker implantation compared to preimplant values overall and in subgroups. In patients with complex congenital heart malformations shortening fraction decreased significantly during the follow up period. (0.45 +/- 0.07 vs 0.35 +/- 0.06, p = 0.015). The correlation between the change in left ventricular shortening fraction and the mean increase of paced QRS duration was not significant. Six patients developed dilated cardiomyopathy, which was diagnosed 2 months to 9 years after pacemaker implantation.
  
  
  CONCLUSIONS
  Chronic right ventricular pacing in pediatric patients with or without structural heart disease does not necessarily result in decline of left ventricular function. In patients with complex congenital heart malformations left ventricular shortening fraction shows significant decrease.
authors.affiliation: Department of Pacing and Clinical Electrophysiology, Gottsegen Gyorgy National Institute of Cardiology, Budapest, Hungary. dr.kardos@t-online.hu
authors.forename: Tchavdar Nikolov
authors.initials: TN
authors.lastname: Shalganov
authors.forename: Dora
authors.initials: D
authors.lastname: Paprika
authors.forename: Radu
authors.initials: R
authors.lastname: Vatasescu
authors.forename: Attila
authors.initials: A
authors.lastname: Kardos
authors.forename: Attila
authors.initials: A
authors.lastname: Mihalcz
authors.forename: Laszlo
authors.initials: L
authors.lastname: Kornyei
authors.forename: Andras
authors.initials: A
authors.lastname: Szatmari
authors.forename: Tamas
authors.initials: T
authors.lastname: Szili-Torok
mesh_terms: D000293:Adolescent; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000009:adverse effects*; D005260:Female; D006330:Heart Defects, Congenital / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology*