title: Left ventricular versus biventricular pacing: a randomized comparative study evaluating mid-term electromechanical and clinical effects.
abstract: BACKGROUND
  Although left ventricular (LV) pacing has been proposed as an alternative to biventricular (BIV) pacing for heart failure (HF) patients, few comparative data are available on the electromechanical effects of these pacing modalities at mid-term follow-up.
  
  
  OBJECTIVE
  To investigate the clinical and echocardiographic effects of LV versus BIV pacing in a mid-term randomized study.
  
  
  METHODS
  After implantation of a device with LV/BIV pacing capabilities, 22 patients with chronic HF and left bundle branch block were randomized to LV or BIV pacing. Patients were assessed both preimplantation and after 3 months by clinical examination, ECG and echocardiography with pulsed tissue Doppler imaging.
  
  
  RESULTS
  At 3 months LV pacing improved clinical parameters, LV ejection fraction (+5%, range 5-8%, P = 0.007) and intraventricular dyssynchrony (-40 ms, range -50 to -15 ms, in septal to lateral delay, P = 0.008) to a similar extent to BIV pacing. A decrease in interventricular mechanical delay (-25 ms, range -40 to -5 ms, P = 0.008) and QRS duration (-28 ms, range -40 to -5 ms, P = 0.008) was observed in BIV, but not in LV patients.
  
  
  CONCLUSIONS
  In this pilot evaluation, LV pacing appeared to be associated with clinical benefits similar to BIV pacing at mid-term follow-up, and this was combined with an improvement in intraventricular dyssynchrony, regardless of variations in interventricular dyssynchrony and QRS duration. Echocardiographic evaluation of intraventricular dyssynchrony seems to be an appropriate method for assessing the chronic response to LV pacing.
authors.affiliation: Institute of Cardiology, University of Bologna and Azienda Ospedaliera S.Orsola-Malpighi, Bologna, Italy. cinzia.valzania2@studio.unibo.it
authors.forename: Cinzia
authors.initials: C
authors.lastname: Valzania
authors.forename: Guido
authors.initials: G
authors.lastname: Rocchi
authors.forename: Mauro
authors.initials: M
authors.lastname: Biffi
authors.forename: Cristian
authors.initials: C
authors.lastname: Martignani
authors.forename: Matteo
authors.initials: M
authors.lastname: Bertini
authors.forename: Igor
authors.initials: I
authors.lastname: Diemberger
authors.forename: Elena
authors.initials: E
authors.lastname: Biagini
authors.forename: Matteo
authors.initials: M
authors.lastname: Ziacchi
authors.forename: Giulia
authors.initials: G
authors.lastname: Domenichini
authors.forename: Davide
authors.initials: D
authors.lastname: Saporito
authors.forename: Claudio
authors.initials: C
authors.lastname: Rapezzi
authors.forename: Angelo
authors.initials: A
authors.lastname: Branzi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D010865:Pilot Projects; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology