title: Triple-site pacing for cardiac resynchronization in permanent atrial fibrillation - Acute phase results from a prospective observational study.
abstract: OBJECTIVE
  Multi-site pacing is emerging as a new method for improving response to cardiac resynchronization therapy (CRT), but has been little studied, especially in patients with atrial fibrillation. We aimed to assess the effects of triple-site (Tri-V) vs. biventricular (Bi-V) pacing on hemodynamics and QRS duration.
  
  
  METHODS
  This was a prospective observational study of patients with permanent atrial fibrillation and ejection fraction <40% undergoing CRT implantation (n=40). One right ventricular (RV) lead was implanted in the apex and another in the right ventricular outflow tract (RVOT) septal wall. A left ventricular (LV) lead was implanted in a conventional venous epicardial position. Cardiac output (using the FloTrac™ Vigileo™ system), mean QRS and ejection fraction were calculated.
  
  
  RESULTS
  Mean cardiac output was 4.81±0.97 l/min with Tri-V, 4.68±0.94 l/min with RVOT septal and LV pacing, and 4.68±0.94 l/min with RV apical and LV pacing (p<0.001 for Tri-V vs. both BiV). Mean pre-implantation QRS was 170±25 ms, 123±18 ms with Tri-V, 141±25 ms with RVOT septal pacing and LV pacing and 145±19 with RV apical and LV pacing (p<0.001 for Tri-V vs. both BiV and pre-implantation). Mean ejection fraction was significantly higher with Tri-V (30±11%) vs. Bi-V pacing (28±12% with RVOT septal and LV pacing and 28±11 with RV apical and LV pacing) and pre-implantation (25±8%).
  
  
  CONCLUSIONS
  Tri-V pacing produced higher cardiac output and shorter QRS duration than Bi-V pacing. This may have a significant impact on the future of CRT.
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal. Electronic address: pedroncmarques@gmail.com.
authors.forename: Pedro
authors.initials: P
authors.lastname: Marques
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Nobre Menezes
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Lima da Silva
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Bernardes
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: Andreia
authors.initials: A
authors.lastname: Magalhães
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Cortez-Dias
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Carpinteiro
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: de Sousa
authors.affiliation: Cardiology Department, University Hospital Santa Maria, Centro Hospitalar de Lisboa Norte, CCUL, University of Lisbon, Portugal.
authors.forename: Fausto J
authors.initials: FJ
authors.lastname: Pinto
mesh_terms: D001281:Atrial Fibrillation / Q000628:therapy*; D002304:Cardiac Pacing, Artificial; D058406:Cardiac Resynchronization Therapy; D004562:Electrocardiography; D006333:Heart Failure; D006801:Humans; D011446:Prospective Studies; D016896:Treatment Outcome
keywords: Atrial fibrillation; Cardiac output; Cardiac resynchronization therapy; Duração QRS; Débito cardiaco; Ejection fraction; Fibrilhação auricular; Fração de ejeção; Heart failure; Insuficiência cardíaca; Multi-site pacing; Pacing multi-site; Pacing triple-site; QRS duration; Terapêutica de ressincronização cardíaca; Triple-site pacing