title: Left ventricular asynchrony in patients with right bundle branch block and normal ejection fraction.
abstract: OBJECTIVE
  The role of right bundle branch block (RBBB) for the induction of left ventricular (LV) asynchrony is discussed controversially. The objective of this study was to assess presence and degree of LV asynchrony in patients with RBBB, left bundle branch block (LBBB), or left anterior hemiblock (LAH) and normal LV function.
  
  
  METHODS
  We included 15 patients with RBBB, 13 patients with RBBB and concomitant LAH, 10 patients with pure LBBB, and 100 healthy controls into this study. All patients had normal LV function. Interventricular asynchrony was assessed as the difference of the right and LV ejection delay. Intraventricular delay was obtained by tissue synchronicity imaging-guided tissue Doppler imaging measurement.
  
  
  RESULTS
  Interventricular and left intraventricular asynchrony were linked to the presence of an LBBB. No left intraventricular asynchrony was noted during pure RBBB; interventricular delays were negative (aortic flow preceding pulmonary flow) in the presence of RBBB.
  
  
  CONCLUSIONS
  In patients with normal LV function, intraventricular asynchrony depends on the presence of an LBBB and interventricular asynchrony is inversed in the presence of RBBB.
authors.affiliation: Medtronic Inc., Bakken Research Center, Maastricht, The Netherlands. berthold.stegemann@medtronic.com
authors.forename: Berthold
authors.initials: B
authors.lastname: Stegemann
authors.forename: Henryk
authors.initials: H
authors.lastname: Dreger
authors.forename: Bruno
authors.initials: B
authors.lastname: Ismer
authors.forename: Gert
authors.initials: G
authors.lastname: Baumann
authors.forename: Christoph
authors.initials: C
authors.lastname: Melzer
mesh_terms: D002037:Bundle-Branch Block / Q000150:complications* / Q000000981:diagnostic imaging*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000000981:diagnostic imaging*