title: Left ventricular pacing in neonates and infants with isolated congenital complete or advanced atrioventricular block: short- and medium-term outcome.
abstract: OBJECTIVE
  Right ventricular (RV) pacing may induce left ventricular (LV) dysfunction: neonates and infants with isolated congenital complete/advanced atrioventricular block (CCAVB) are at high risk of developing RV pacing-induced LV dyssynchrony, remodelling, and dysfunction. We prospectively investigated whether LV pacing results in normal LV function and good clinical status in the short/medium term.
  
  
  RESULTS
  In this single-centre, prospective study, 10 consecutive patients with CCAVB (median age 4 months, range: 0.1-16) underwent pacemaker implantation (4 VVIR, 6 DDD) using epicardial leads (on the LV apex in 8, on the LV free wall in 2). Data were collected at implantation and at 1- and 12-month follow-up. Echocardiographic evaluation included two-dimensional/three-dimensional assessment of LV dimensions, function (ejection fraction, EF), and ventricular synchrony (interventricular and intraventricular dyssynchrony). Prior to pacemaker implantation, EF was normal in six patients, 50% in two, ≤40% in two. All patients showed good clinical status and normal LV dimensions at follow-up. Patients with LV dilatation and impaired EF at implantation showed LV reverse remodelling and enhanced LV function. Normal LV function and synchrony were observed in most patients (one patient with EF 53% and three patients with mild dyssynchrony at 12-month follow-up). Paced QRS complex tended to be wider than native QRS complexes (P = 0.07); QTc duration of paced complexes was within normal limits or only slightly prolonged, without significant differences compared with QTc interval of native complexes.
  
  
  CONCLUSIONS
  At short- and medium-term follow-up, LV pacing results in satisfactory LV electromechanical function and synchrony in neonates and infants with CCAVB.
authors.affiliation: Arrhythmia Unit and Syncope Unit, Department of Paediatric Cardiology, Bambino Gesù Children's Hospital, IRCCS, Via Torre di Palidoro 1, 00050 Palidoro-Rome, Italy silvetti@opbg.net.
authors.forename: Massimo Stefano
authors.initials: MS
authors.lastname: Silvetti
authors.affiliation: Cardiac Surgery Unit, Bambino Gesù Children's Hospital, IRCCS, 00100 Rome, Italy.
authors.forename: Duccio
authors.initials: D
authors.lastname: Di Carlo
authors.affiliation: Arrhythmia Unit and Syncope Unit, Department of Paediatric Cardiology, Bambino Gesù Children's Hospital, IRCCS, Via Torre di Palidoro 1, 00050 Palidoro-Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ammirati
authors.affiliation: Arrhythmia Unit and Syncope Unit, Department of Paediatric Cardiology, Bambino Gesù Children's Hospital, IRCCS, Via Torre di Palidoro 1, 00050 Palidoro-Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Placidi
authors.affiliation: Arrhythmia Unit and Syncope Unit, Department of Paediatric Cardiology, Bambino Gesù Children's Hospital, IRCCS, Via Torre di Palidoro 1, 00050 Palidoro-Rome, Italy.
authors.forename: Corrado
authors.initials: C
authors.lastname: Di Mambro
authors.affiliation: Epidemiology Unit, Bambino Gesù Children's Hospital, IRCCS, 00100 Rome, Italy.
authors.forename: Lucilla
authors.initials: L
authors.lastname: Ravà
authors.affiliation: Arrhythmia Unit and Syncope Unit, Department of Paediatric Cardiology, Bambino Gesù Children's Hospital, IRCCS, Via Torre di Palidoro 1, 00050 Palidoro-Rome, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Drago
mesh_terms: D054537:Atrioventricular Block / Q000151:congenital* / Q000175:diagnosis / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D016896:Treatment Outcome
keywords: Alternative pacing sites; Cardiac pacing; Children; Congenital atrioventricular block; Heart failure