title: Use of left ventricular pacing in heart failure: evaluation by gated blood pool imaging.
abstract: BACKGROUND
  Left ventricular (LV) pacing has been suggested to complement other forms of therapy in patients with heart failure.
  
  
  RESULTS
  We investigated 17 patients (15 men, 2 women, aged 68 +/- 6 years, 10 ischemic and 7 primary dilated cardiomyopathy) with heart failure (13 were in New York Heart Association class IV and 4 in class III). One month after LV pacer implantation, 12 patients reported clinical improvement (mean class 3.7 before pacing vs 2.6 with LV pacing; P = .001). We report the results of 3 equilibrium-gated blood pool studies performed in each patient, 1 before pacing and 2 after pacer implantation (1 with pacing on, and 1 after turning off the pacer). LV pacing did not modify LV ejection fraction. Phase analysis demonstrated a significant decrease of the interventricular phase shift (delta(pi)) with LV pacing (no pacing, delta(pi) = 8.99 degrees +/- 19.05 degrees; delta7n= -0.97 degrees +/- 27.85 degrees with LV pacing). Clinical improvement was observed in patients with an initial positive delta(pi) that decreased with pacing and/or an initial LV phase standard deviation >50 degrees that decreased with pacing.
  
  
  CONCLUSIONS
  LV pacing induces interventricular and intraventricular synchronization. A decrease of the interventricular phase shift seems to be the most important predictor of functional recovery for paced patients with heart failure.
authors.affiliation: Department of Nuclear Medicine, University Hospital Cavale Blanche, Brest, France.
authors.forename: C
authors.initials: C
authors.lastname: Le Rest
authors.forename: O
authors.initials: O
authors.lastname: Couturier
authors.forename: A
authors.initials: A
authors.lastname: Turzo
authors.forename: P
authors.initials: P
authors.lastname: Guillo
authors.forename: Y
authors.initials: Y
authors.lastname: Bizais
authors.forename: Y
authors.initials: Y
authors.lastname: Etienne
authors.forename: J J
authors.initials: JJ
authors.lastname: Blanc
authors.forename: J
authors.initials: J
authors.lastname: Narula
mesh_terms: D000368:Aged; D002302:Cardiac Output / Q000502:physiology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002311:Cardiomyopathy, Dilated / Q000150:complications; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D015637:Gated Blood-Pool Imaging; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D017202:Myocardial Ischemia / Q000150:complications; D010138:Pacemaker, Artificial; D020127:Recovery of Function; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right / Q000502:physiology