title: Ventricular electrical activation in cardiac resynchronization as characterized by body surface potential mapping.
abstract: OBJECTIVE
  To assess cardiac electrical activation by using body surface potential mapping (BSPM), in patients with congestive heart failure (CHF) and left bundle branch block (LBBB) undergoing cardiac resynchronization therapy (CRT) with biventricular pacemaker (BIV-PM) implantation.
  
  
  METHODS
  Mean cardiac electrical activation times were analyzed in the right ventricle (RV) (mean RV activation time = mRV), anteroseptal area (mAS), and left ventricle (mLV) of 28 patients (mean age 61.2 +/- 9.5 years; NYHA class III-IV CHF; ejection fraction <40%; LBBB of mean QRS 181.2+/-19.4 ms, SAQRS -8.5 masculine+/-68.6 masculine), as shown in their BSPM isochronous maps, before and after implantation of atriobiventricular pacemaker, comparing those with values obtained from a control group of normal individuals [CG], in three situations: (1) native LBBB; (2) RV pacing; and (3) atriobiventricular pacing.
  
  
  RESULTS
  Situation (1): mRV and mAS values were similar (41.0+/-11.8 ms x 43.6+/-13.4 ms), with delayed mLV (81.0+/-12.5 ms, p<0.01) and asynchronous with RV and AS areas; situation (2): mRV was greater than in CG (86.8+/-22.9 ms, p<0.001), with greater difference between mAS and mLV (63.4+/-20.7 ms vs. 102.7+/-20.3 ms; p<0,001); situation (3): mLV and mRV were similar (72.0+/-32.0 ms vs. 71.6+/-32.3 ms), mRV was greater than in CG and native LBBB (71.6+/-32.3 ms vs. 35.1+/-10.9 ms and 41.0+/-11.8 ms; p<0.001), and mAS was close to CG and native LBBB values (51.3+/-32.8 ms vs. 50.1+/-11.4 ms and 43.6+/-13.4 ms).
  
  
  CONCLUSIONS
  The body surface potential mapping showed that RV and LV activation times which are similar, and are close to those of the AS area, suggest patterns of synchronized ventricular activation in patients with CHF and LBBB during atriobiventricular pacing.
authors.affiliation: Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil. ecg_pastore@incor.usp.br
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Pastore
authors.forename: Nancy
authors.initials: N
authors.lastname: Tobias
authors.forename: Nelson
authors.initials: N
authors.lastname: Samesima
authors.forename: Martino
authors.initials: M
authors.lastname: Martinelli Filho
authors.forename: Anisio
authors.initials: A
authors.lastname: Pedrosa
authors.forename: Silvana
authors.initials: S
authors.lastname: Nishioka
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Douglas
authors.forename: Luiz Felipe Pinho
authors.initials: LF
authors.lastname: Moreira
authors.forename: José Franchini
authors.initials: JF
authors.lastname: Ramires
mesh_terms: D018780:Body Surface Potential Mapping; D002037:Bundle-Branch Block / Q000503:physiopathology* / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D016022:Case-Control Studies; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D013997:Time Factors; D016276:Ventricular Function / Q000502:physiology