title: Multipoint pacing by a left ventricular quadripolar lead improves the acute hemodynamic response to CRT compared with conventional biventricular pacing at any site.
abstract: BACKGROUND
  Response to cardiac resynchronization therapy (CRT) remains challenging. Pacing from multiple sites of the left ventricle (LV) has shown promising results.
  
  
  OBJECTIVE
  The purpose of this study was to systematically compare the acute hemodynamic effects of multipoint pacing (MPP) by means of a quadripolar lead with conventional biventricular (BiV) pacing.
  
  
  METHODS
  Twenty-nine patients (23 men; mean age 72 ± 12 years; LV ejection fraction 29% ± 7%; 15 with ischemic cardiomyopathy, 17 with left bundle branch block; mean QRS 183 ± 23 ms) underwent CRT implantation. Per patient, 3.2 ± 1.2 different veins and 6.3 ± 2.4 pacing sites were tested. LV electrical delay (Q-LV) was measured at each location, along with the increase in LV dP/dtmax (maximum rate of rise of LV pressure) obtained by BiV and MPP. The effect of MPP, by means of simultaneous pacing from distal and proximal dipoles, was investigated at all available sites.
  
  
  RESULTS
  Overall, 3.2 ± 1.2 different MPP measurements were collected per patient. When all sites were considered, LV dP/dtmax increased from 951 ± 193 mm Hg/s at baseline to 1144 ± 255 and 1178 ± 259 mm Hg/s on BiV and MPP, respectively. When the best site was considered, LV dP/dtmax increased from a baseline value of 942 ± 202 mm Hg/s to 1200 ± 267 mm Hg/s (BiV) and 1231 ± 267 mm Hg/s (MPP). The mean QRS duration at any site during MPP and conventional CRT was 171 ± 18 and 175 ± 16 ms (P = .003), respectively.
  
  
  CONCLUSIONS
  Compared with BiV pacing at any LV site, MPP yielded a small but consistent increase in hemodynamic response. A correlation between the increase in hemodynamics and Q-LV on MPP was observed for all measurements, including those taken at the best and worst sites. The MPP-induced improvement in contractility was associated with significantly greater narrowing of the QRS complex than conventional BiV pacing.
authors.affiliation: Arrhythmia and Electrophysiology Unit, Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy. Electronic address: franc.zanon@iol.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Zanon
authors.affiliation: Arrhythmia and Electrophysiology Unit, Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Baracca
authors.affiliation: Arrhythmia and Electrophysiology Unit, Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Pastore
authors.affiliation: Arrhythmia and Electrophysiology Unit, Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Lina
authors.initials: L
authors.lastname: Marcantoni
authors.affiliation: Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Fraccaro
authors.affiliation: Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Lanza
authors.affiliation: Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Picariello
authors.affiliation: Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Silvio
authors.initials: S
authors.lastname: Aggio
authors.affiliation: Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Loris
authors.initials: L
authors.lastname: Roncon
authors.affiliation: Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Dell'Avvocata
authors.affiliation: Cardiology Department, Santa Maria Della Misericordia Hospital, Rovigo, Italy.
authors.forename: GianLuca
authors.initials: G
authors.lastname: Rigatelli
authors.affiliation: St. Jude Medical, Agrate Brianza, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Pacetta
authors.affiliation: Department of Molecular Medicine, University of Padua, Padua, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Noventa
authors.affiliation: Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands.
authors.forename: Frits W
authors.initials: FW
authors.lastname: Prinzen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000379:methods; D058409:Cardiac Resynchronization Therapy Devices / Q000009:adverse effects / Q000145:classification; D009202:Cardiomyopathies / Q000150:complications* / Q000503:physiopathology; D057186:Comparative Effectiveness Research; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D004867:Equipment Design; D005260:Female; D006333:Heart Failure / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017755:Prosthesis Fitting; D013318:Stroke Volume
keywords: Cardiac resynchronization therapy; Hemodynamics; Multipoint pacing