title: Acute effects of biventricular pacing on right ventricular function assessed by tissue Doppler imaging.
abstract: OBJECTIVE
  The benefits of cardiac resynchronization therapy (CRT) on functional status, left ventricular (LV) remodelling and survival in patients with drug-refractory congestive heart failure (CHF), LV systolic dysfunction, and wide QRS have been demonstrated in randomized trials. However, the impact of CRT on right ventricular (RV) function, an independent prognostic factor in CHF remains questionable. This study examined the acute effects of various pacing modes on RV function in recipients of CRT systems.
  
  
  RESULTS
  Echocardiographic examinations were performed in 15 patients (median age: 67 years, range 49-78), to compare RV function during atrial (AAI), RV and LV pacing, and biventricular (BiV) pacing, in random order. At baseline, the median LV ejection fraction was 20% (range 10-35) and the median LV end-diastolic diameter was 78 mm (range 62-85). Right ventricular function was impaired, with a median 36% fractional shortening of RV surfaces (7-59). Tissue Doppler systolic peak of velocity (Sa) recorded at the tricuspid annulus increased significantly from 9.9 cm/s (range 4.7-16.5) during AAI pacing, 10 cm/s (range 5.4-20.3) during RV pacing, and 11.7 cm/s (range 4.6-16.7) during LV pacing to 12.6 cm/s (range 6.6-19.1) during BiV pacing (P < 0.01). Trends toward improvements in other indices of RV function, particularly myocardial performance index and systolic excursion of the tricuspid annulus, were also observed.
  
  
  CONCLUSIONS
  This short-term study showed a significant improvement in RV systolic function during BiV pacing compared with AAI, RV, or LV pacing in CRT recipients.
authors.affiliation: Department of Cardiology, University Hospital Pontchaillou, 35033 Rennes, France.
authors.forename: Erwan
authors.initials: E
authors.lastname: Donal
authors.forename: Noëlle
authors.initials: N
authors.lastname: Vignat
authors.forename: Christian
authors.initials: C
authors.lastname: De Place
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Leray
authors.forename: Christophe
authors.initials: C
authors.lastname: Crocq
authors.forename: Philippe
authors.initials: P
authors.lastname: Mabo
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Daubert
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D016278:Ventricular Function, Right