title: Outcome in young patients with isolated complete atrioventricular block and permanent pacemaker treatment: A nationwide study of 127 patients.
abstract: BACKGROUND
  Subgroups of pacemaker (PM)-treated children with isolated complete atrioventricular block are at risk of developing left ventricular (LV) dysfunction.
  
  
  OBJECTIVE
  We aimed to compare the long-term outcome in anti-SSA-Ro/SSB-La antibody-exposed (AB+) and unexposed (AB-) patients and identify preimplantation variables associated with poor outcome.
  
  
  METHODS
  In total, 127 PM-treated patients aged 0-17 years with isolated complete atrioventricular block were studied retrospectively.
  
  
  RESULTS
  Sixty-three patients were diagnosed prenatally, of whom 92% were AB+. Before PM treatment, fractional shortening (FS) z-score was significantly lower in AB+ patients than in AB- patients (-0.14 ± 3.6 vs 2.03 ± 2.3). Before PM implantation, there were sex differences (male/female) in median time from diagnosis to PM implantation (0.2 years vs 1.0 years), median neonatal heart rate (50 beats/min vs 60 beats/min), left ventricular end-diastolic dimension (LVEDD) z-score (2.68 ± 1.41 vs 1.74 ± 1.40), and FS (-0.19 ± 3.38 vs 1.42 ± 2.98). The median age at PM implantation was 3.2 years, and median follow-up was 8.7 years. At follow-up, LVEDD and FS did not differ significantly between AB+ and AB- patients, but LVEDD was higher in patients diagnosed before 1 month of age. Nine patients (8%) developed LV dysfunction, and 4 died. LV dysfunction was associated with diagnosis before 1 month of age and abnormal LV function before PM implantation.
  
  
  CONCLUSIONS
  LV dysfunction at follow-up was seen only in cases diagnosed before 1 month, with abnormal echocardiography before PM implantation. Boys had a more compromised cardiac status and were paced at an earlier age than girls. Fetal AB exposure and male sex were related to abnormal LV function before PM therapy, but not at follow-up.
authors.affiliation: Department of Women's and Children's Health. Electronic address: hakan.eliasson@karolinska.se.
authors.forename: Håkan
authors.initials: H
authors.lastname: Eliasson
authors.affiliation: Department of Women's and Children's Health.
authors.forename: Sven-Erik
authors.initials: SE
authors.lastname: Sonesson
authors.affiliation: Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Stina
authors.initials: S
authors.lastname: Salomonsson
authors.affiliation: Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Amanda
authors.initials: A
authors.lastname: Skog
authors.affiliation: Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Wahren-Herlenius
authors.affiliation: Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Gadler
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000906:Antibodies / Q000097:blood; D054537:Atrioventricular Block / Q000151:congenital* / Q000276:immunology / Q000401:mortality / Q000628:therapy*; D001324:Autoantigens / Q000097:blood; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015150:Echocardiography, Doppler; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors; D015996:Survival Rate; D013548:Sweden; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D055815:Young Adult
chemical_list: D000906:Antibodies; D001324:Autoantigens
keywords: Atrioventricular block; Left ventricular dysfunction; Pacemaker; Pediatric