title: Ventricular pacing lead location alters systemic hemodynamics and left ventricular function in patients with and without reduced ejection fraction.
abstract: OBJECTIVE
  We compared left ventricular (LV) systolic and diastolic function during right ventricular (RV), LV, and biventricular (BiV) pacing in patients with narrow QRS duration with and without LV dysfunction.
  
  
  BACKGROUND
  The optimal RV pacing lead location for patients with a standard indication for ventricular pacing remains controversial.
  
  
  METHODS
  Left ventricular pressure and volume data were determined via conductance catheter during electrophysiology study in 31 patients divided into groups with ejection fraction (EF) > or =40% (n = 17) or EF <40% (n = 14). QRS duration was 91 +/- 18 versus 106 +/- 25 ms, respectively (p = NS). Hemodynamic data were recorded during atrial and dual chamber pacing from the RV apex, RV free wall, RV septum, LV free wall, and BiV.
  
  
  RESULTS
  In patients with EF > or =40%, RV pacing at 1 or more sites, but not LV free wall or BiV pacing, significantly (p < 0.05) impaired cardiac output (CO), stroke work (SW), EF, and LV relaxation compared with atrial overdrive pacing. Right ventricular pacing also impaired hemodynamics and LV function in patients with EF <40%. However, LV and BiV pacing increased CO, SW, EF, and LV +dP/dt(MAX) in patients with LV dysfunction. Left ventricular and BiV pacing enhanced an index of global LV cycle efficiency in patients with depressed EF. The detrimental hemodynamic effects of RV pacing were attenuated by selecting the optimal RV pacing site.
  
  
  CONCLUSIONS
  Right ventricular pacing worsens LV function in patients with and without LV dysfunction unless the RV pacing site is optimized. Left ventricular and BiV pacing preserve LV function in patients with EF >40% and improve function in patients with EF <40% despite no clinical indication for BiV pacing.
authors.affiliation: Department of Cardiology, Harper University Hospital, Detroit, Michigan 48201, USA. rlieberm@dmc.org
authors.forename: Randy
authors.initials: R
authors.lastname: Lieberman
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
authors.forename: Jan
authors.initials: J
authors.lastname: Schreuder
authors.forename: Kenneth
authors.initials: K
authors.lastname: Jackson
authors.forename: Antonio
authors.initials: A
authors.lastname: Michelucci
authors.forename: Andrea
authors.initials: A
authors.lastname: Colella
authors.forename: William
authors.initials: W
authors.lastname: Eastman
authors.forename: Sergio
authors.initials: S
authors.lastname: Valsecchi
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Hettrick
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology* / Q000628:therapy*; D002302:Cardiac Output; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography; D004567:Electrodes, Implanted; D006325:Heart Atria; D006352:Heart Ventricles; D006439:Hemodynamics; D006801:Humans; D009200:Myocardial Contraction; D011446:Prospective Studies; D013318:Stroke Volume; D016277:Ventricular Function, Left