title: Biventricular pacing and left ventricular pacing in heart failure: similar hemodynamic improvement despite marked electromechanical differences.
abstract: BACKGROUND
  We conducted an acute echocardiographic study comparing hemodynamic and ventricular dyssynchrony parameters during left ventricular pacing (LVP) and biventricular pacing (BVP). We sought to clarify the mechanisms responsible for similar hemodynamic improvement despite differences in electrical activation.
  
  
  RESULTS
  Thirty-three patients underwent echocardiography prior to implantation with a multisite pacing device (spontaneous rhythm [SR]) and 2 days after implantation (BVP and LVP). Interventricular dyssynchrony (pulsed-wave Doppler), extent of myocardium displaying delayed longitudinal contraction (%DLC; tissue tracking), and index of LV dyssynchrony (pulsed-wave tissue Doppler imaging) were assessed. Compared to SR, BVP and LVP caused similar significant improvement of cardiac output (LVP: 3.2 +/- 0.5, BVP: 3.1 +/- 0.7, SR: 2.3 +/- 0.6 L/min; P < 0.01) and mitral regurgitation (LVP: 25.1 +/- 10, BVP: 24.7 +/- 11, baseline: 37.9 +/- 14% jet area/left atria area; P < 0.01). LVP resulted in a smaller index of LV dyssynchrony than BVP (29 +/- 10 vs 34 +/- 14; P < 0.05). However, LVP exhibited a longer aortic preejection delay (220 +/- 34 vs 186 +/- 28 msec; P < 0.01), longer LV electromechanical delays (244.5 +/- 39 vs 209.5 +/- 47 msec; P < 0.05), greater interventricular dyssynchrony (56.6 +/- 18 vs 31.4 +/- 18; P < 0.01), and higher%DLC (40.1 +/- 08 vs 30.3 +/- 09; P < 0.05), leading to shorter LV filling time (387 +/- 54 vs 348 +/- 44 msec; P < 0.05) compared to BVP.
  
  
  CONCLUSIONS
  Although LVP and BVP provide similar hemodynamic improvement, LVP results in more homogeneous but substantially delayed LV contraction, leading to shortened filling time and less reduction in postsystolic contraction. These data may influence the choice of individual optimal pacing configuration.
authors.affiliation: Hôpital Cardiologique du Haut Lévèque, Pessac, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bordachar
authors.forename: Stephane
authors.initials: S
authors.lastname: Lafitte
authors.forename: Sylvain
authors.initials: S
authors.lastname: Reuter
authors.forename: Stephane
authors.initials: S
authors.lastname: Garrigue
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
authors.forename: Raymond
authors.initials: R
authors.lastname: Roudaut
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
authors.forename: Jacques
authors.initials: J
authors.lastname: Clementy
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002303:Cardiac Output, Low; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy