title: Acute hemodynamic effects of pacing in patients with Fontan physiology: a prospective study.
abstract: OBJECTIVE
  The purpose of this research was to assess the hemodynamic response to atrial, ventricular, and dual-chamber pacing in patients with Fontan physiology.
  
  
  BACKGROUND
  Bradycardia, due to sinus node dysfunction or atrioventricular (AV) block, with need for pacing, is common after the Fontan operation. The optimal pacing mode for Fontan patients is unknown, but is critical, as hemodynamic aberrancies may cause severe clinical deterioration. We hypothesized that AV synchrony is vital for maximizing Fontan hemodynamics.
  
  
  METHODS
  A cross-over trial was conducted with 21 patients (age 2 to 18 years, median 4 years; male patients = 13) in the intensive care unit after a Fontan operation. Hemodynamic parameters, including mean left atrial pressure (LAP, in mm Hg), mean pulmonary artery pressure (PAP, in mm Hg), mean arterial blood pressure (MAP, in mm Hg), and indexed cardiac output via Fick (Qs, in l/min/m2) were measured with atrial, ventricular, and dual-chamber pacing. Measurements were made after pacing for 10 min in each mode, and a 10-min rest was given between each pacing maneuver.
  
  
  RESULTS
  Asynchronous ventricular (VOO) pacing resulted in significantly worse hemodynamics when compared to dual-chamber (DOO) and atrial (AOO) pacing with a higher LAP (9.4 VOO; 6.8 DOO; 5.4 AOO) and PAP (15.2 VOO; 13.5 DOO; 12.7 AOO) and lower Qs (3.0 VOO; 3.5 DOO; 3.9 AOO) and MAP (60.1 VOO; 66.5 DOO; 67.2 AOO).
  
  
  CONCLUSIONS
  Asynchronous ventricular pacing, after the Fontan procedure, has acute, adverse hemodynamic consequences (elevated LAP and PAP and decreased Qs and MAP).
authors.affiliation: Department of Pediatric Cardiology, Oregon Health & Science University, Portland, Oregon, USA. barberb@peds.arizona.edu
authors.forename: Brent J
authors.initials: BJ
authors.lastname: Barber
authors.forename: Anjan S
authors.initials: AS
authors.lastname: Batra
authors.forename: Grant H
authors.initials: GH
authors.lastname: Burch
authors.forename: Irving
authors.initials: I
authors.lastname: Shen
authors.forename: Ross M
authors.initials: RM
authors.lastname: Ungerleider
authors.forename: John W
authors.initials: JW
authors.lastname: Brown
authors.forename: Mark W
authors.initials: MW
authors.lastname: Turrentine
authors.forename: Motomi
authors.initials: M
authors.lastname: Mori
authors.forename: Yi-Ching
authors.initials: YC
authors.lastname: Hsieh
authors.forename: Seshadri
authors.initials: S
authors.lastname: Balaji
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D002304:Cardiac Pacing, Artificial; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D005260:Female; D018729:Fontan Procedure; D006321:Heart / Q000502:physiology*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D011446:Prospective Studies