title: Predictors of left ventricular remodelling and failure in right ventricular pacing in the young.
abstract: OBJECTIVE
  To identify risk factors for left ventricular (LV) dysfunction in right ventricular (RV) pacing in the young. methods and results: Left ventricular function was evaluated in 82 paediatric patients with either non-surgical (n = 41) or surgical (n= 41) complete atrioventricular block who have been 100% RV paced for a mean period of 7.4 years. Left ventricular shortening fraction (SF) decreased from a median (range) of 39 (24-62)% prior to implantation to 32 (8-49)% at last follow-up (P < 0.05). Prevalence of a combination of LV dilatation (LV end-diastolic diameter >+2z-values) and dysfunction (SF < 0.26) was found to increase from 1.3% prior to pacemaker implantation to 13.4% (11/82 patients) at last follow-up (P = 0.01). Ten of these 11 patients had progressive LV remodelling and 8 of 11 were symptomatic. The only significant risk factor for the development of LV dilatation and dysfunction was the presence of epicardial RV free wall pacing (OR = 14.3, P < 0.001). Other pre-implantation demographic, diagnostic, and haemodynamic factors including block aetiology, pacing variables, and pacing duration did not show independent significance.
  
  
  CONCLUSIONS
  Right ventricular pacing leads to pathologic LV remodelling in a significant proportion of paediatric patients. The major independent risk factor is the presence of epicardial RV free wall pacing, which should be avoided whenever possible.
authors.affiliation: Kardiocentrum and Cardiovascular Research Center, University Hospital Motol, Prague, Czech Republic.
authors.forename: Roman A
authors.initials: RA
authors.lastname: Gebauer
authors.forename: Viktor
authors.initials: V
authors.lastname: Tomek
authors.forename: Aida
authors.initials: A
authors.lastname: Salameh
authors.forename: Jan
authors.initials: J
authors.lastname: Marek
authors.forename: Václav
authors.initials: V
authors.lastname: Chaloupecký
authors.forename: Roman
authors.initials: R
authors.lastname: Gebauer
authors.forename: Tomás
authors.initials: T
authors.lastname: Matejka
authors.forename: Pavel
authors.initials: P
authors.lastname: Vojtovic
authors.forename: Jan
authors.initials: J
authors.lastname: Janousek
mesh_terms: D000293:Adolescent; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000379:methods; D002648:Child; D002675:Child, Preschool; D003971:Diastole / Q000502:physiology; D005260:Female; D006327:Heart Block / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018570:Risk Assessment; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D020257:Ventricular Remodeling / Q000502:physiology*; D055815:Young Adult