title: A prospective, randomized comparison of the acute hemodynamic effects of biventricular and left ventricular pacing with cardiac resynchronization therapy.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) is most commonly performed with biventricular (BiV) pacing. Left ventricular (LV) only pacing is an alternative pacing configuration for CRT, but comparative studies with BiV pacing have shown inconsistent results. This may be due to differences in LV activation pattern, which could be differentially affected by atriventricular (AV) programming or atrial pacing (AP).
  
  
  OBJECTIVE
  The purpose of this study was to compare AV optimization and the effect of atrial overdrive pacing on the acute hemodynamic response of LV and BiV CRT.
  
  
  METHODS
  This study included 28 patients undergoing CRT. At implant, invasive LV dP/dt was measured by a micromanometer catheter during BiV or LV pacing in atrial sensing (AS) and AP modes at five different AV delays (AVDs), tested in randomized order.
  
  
  RESULTS
  Compared with intrinsic rhythm, CRT with AS increased LV dP/dt by 12% ± 10% during LV pacing and by 11% ± 11% during BiV pacing (P = .15). With atrial overdrive pacing, CRT increased LV dP/dt by 17% ± 10% with LV pacing and by 17% ± 11% during BiV pacing (P = NS vs. LV; P <.001 vs. AS). The optimal AVD was significantly longer with AP (LV 202 ± 63 ms vs. 131 ± 42 ms during AS; BiV 195 ± 71 ms vs. 134 ± 43 ms during AS) but did not differ between LV and BiV pacing.
  
  
  CONCLUSIONS
  In this study, AP increases LV dP/dt during CRT but requires a substantially longer AVD. However, the optimal AVDs were similar for LV and BiV as were the magnitudes of the responses during CRT, suggesting that programmed AVDs are interchangeable in these two configurations.
authors.affiliation: Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina 29425, USA. goldmr@musc.edu
authors.forename: Michael R
authors.initials: MR
authors.lastname: Gold
authors.forename: Imran
authors.initials: I
authors.lastname: Niazi
authors.forename: Michael
authors.initials: M
authors.lastname: Giudici
authors.forename: Robert B
authors.initials: RB
authors.lastname: Leman
authors.forename: J Lacy
authors.initials: JL
authors.lastname: Sturdivant
authors.forename: Michael H
authors.initials: MH
authors.lastname: Kim
authors.forename: Yinghong
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies