title: Improvement in acute contractility and hemodynamics with multipoint pacing via a left ventricular quadripolar pacing lead.
abstract: BACKGROUND
  A quadripolar left ventricular (LV) pacing can deliver multipoint pacing (MPP). It is unknown if this confers improved cardiac function compared to conventional cardiac resynchronization therapy (CRT).
  
  
  RESULTS
  We aimed to characterize changes in acute cardiac contractility and hemodynamics with multisite left ventricular "multipoint" pacing (MPP) in a prospective multicenter study in patients implanted with a CRT-defibrillator incorporating a quadripolar LV lead. The device was programmed to deliver MPP acutely pacing with eight configurations of varying timing delays. Global peak LV radial strain and LV outflow velocity time integral (LVOT VTI) were measured for conventional CRT and each MPP configuration. Out of the eight tested MPP configurations, the one that yielded the best echocardiographic measurement for each patient was defined as "optimal MPP". Forty CRT recipients had complete radial strain datasets suitable for analysis. Compared to conventional CRT, the mean peak radial strain was significantly higher for the optimal MPP configuration (18.3 ± 7.4 vs. 9.3 ± 5.3%, p < 0.001), and at least one MPP configuration was significantly superior (>20%) in 63% of patients. LVOT VTI data were collected in a subset of 13 patients. In these patients, mean VTI was significantly higher for optimal MPP compared to conventional CRT (13.5 ± 2.7 vs. 10.9 ± 3.3 cm, p < 0.01).
  
  
  CONCLUSIONS
  MPP delivered via a quadripolar LV lead resulted in a significant improvement in acute cardiac contractility and hemodynamics compared to conventional CRT in the majority of patients studied.
  
  
  BACKGROUND
  Clinicaltrials.gov identifier NCT01044784.
authors.affiliation: Cardiac Department, St Thomas' Hospital, London, SE1 7EH, UK, c.rinaldi@virgin.net.
authors.forename: C Aldo
authors.initials: CA
authors.lastname: Rinaldi
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kranig
authors.forename: Salem
authors.initials: S
authors.lastname: Kacet
authors.forename: Tim
authors.initials: T
authors.lastname: Betts
authors.forename: Pierre
authors.initials: P
authors.lastname: Bordachar
authors.forename: Klaus-Jürgen
authors.initials: KJ
authors.lastname: Gutleben
authors.forename: Anoop
authors.initials: A
authors.lastname: Shetty
authors.forename: Erwan
authors.initials: E
authors.lastname: Donal
authors.forename: Allen
authors.initials: A
authors.lastname: Keel
authors.forename: Kyungmoo
authors.initials: K
authors.lastname: Ryu
authors.forename: Taraneh G
authors.initials: TG
authors.lastname: Farazi
authors.forename: Marcus
authors.initials: M
authors.lastname: Simon
authors.forename: Tasneem Z
authors.initials: TZ
authors.lastname: Naqvi
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011446:Prospective Studies