title: Acute hemodynamic benefit of left ventricular apex pacing in children.
abstract: BACKGROUND
  Despite the fact that pacing at the right ventricular apex acutely and chronically decreases left ventricular contractile function, this pacing site is still conventionally used in adults and children. Because animal studies showed beneficial effects of left ventricular pacing, we compared the hemodynamic performance of left ventricular apex, left ventricular free wall, and right ventricular apex pacing in children.
  
  
  METHODS
  Studies were performed in 10 children (median age, 2.5 years; range, 2 months to 17 years) undergoing surgery for congenital heart disease with normal systemic left ventricular anatomy and intraventricular conduction. High-fidelity left ventricular and arterial pressure measurements were performed during epicardial right ventricular apex and left ventricular apex and free wall pacing.
  
  
  RESULTS
  Left ventricular apex pacing increased the maximum rate of rise of left ventricular pressure and pulse pressure significantly relative to right ventricular apex pacing (by 7.7% +/- 7.2% and 7.7% +/- 7.0%, respectively) without changes in end-diastolic left ventricular pressure. Left ventricular free wall pacing did not significantly improve hemodynamics as compared with right ventricular apex pacing. The QRS duration was not different among pacing at the three sites.
  
  
  CONCLUSIONS
  In this short-term study left ventricular apex pacing is hemodynamically superior to right ventricular apex and left ventricular free wall pacing in children. Therefore, the left ventricular apex appears a favorable pacing site after pediatric cardiac surgery.
authors.affiliation: Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands.
authors.forename: Ward Y
authors.initials: WY
authors.lastname: Vanagt
authors.forename: Xander A
authors.initials: XA
authors.lastname: Verbeek
authors.forename: Tammo
authors.initials: T
authors.lastname: Delhaas
authors.forename: Marc
authors.initials: M
authors.lastname: Gewillig
authors.forename: Luc
authors.initials: L
authors.lastname: Mertens
authors.forename: Patrick
authors.initials: P
authors.lastname: Wouters
authors.forename: Bart
authors.initials: B
authors.lastname: Meyns
authors.forename: Willem J
authors.initials: WJ
authors.lastname: Daenen
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
mesh_terms: D000293:Adolescent; D002304:Cardiac Pacing, Artificial; D002648:Child; D002675:Child, Preschool; D005260:Female; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery*; D006352:Heart Ventricles; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D008297:Male