title: Left ventricular function and visual phase analysis with equilibrium radionuclide angiography in patients with biventricular device.
abstract: OBJECTIVE
  Cardiac resynchronisation therapy (CRT) is a technique indicated in patients with moderate to severe heart failure and ventricular dyssynchrony. To evaluate left ventricular ejection fraction (LVEF) and synchronisation changes after CRT with a biventricular pacing implant, we used an equilibrium radionuclide angiography (ERNA).
  
  
  METHODS
  Fifty patients were studied. An ERNA was made 72 h and 6 months after the implant. Two acquisitions were performed: with the CRT device connected and after disconnecting it. In the follow-up, responders were defined as those who had improved in accordance with various clinical variables. Quantitative changes in LVEF and visual changes in synchronisation (phase analysis) were studied comparing the two studies and also comparing the connected and disconnected modes.
  
  
  RESULTS
  At 6 months, 30 patients were defined as responders. LVEF increased significantly at 6 months compared with the 72-h study only in responders. At 72 h, the number of patients showing a decrease in LVEF (p < 0.05) or a synchronisation worsening after disconnecting the device was higher in responders than in nonresponders. At 6 months, 57% of responders had no synchronisation changes between the connected and disconnected modes, suggesting a resynchronisation process.
  
  
  CONCLUSIONS
  ERNA permits the study of resynchronisation patients, showing a statistical LVEF improvement at 6 months. Moreover, visual phase analysis permits the study of the mechanism involved in the response, with an important number of responders with no changes between the two modes at 6 months. In the 72-h study, after disconnection of the device, LVEF and resynchronisation worsening can predict patient improvement at 6 months.
authors.affiliation: Nuclear Medicine Department (Centre de Diagnóstic per la Imatge, CDI), Hospital Clínic, Universitat de Barcelona, Villarroel 170, 08036 Barcelona, Spain. amuxi@clinic.ub.es
authors.forename: Africa
authors.initials: A
authors.lastname: Muxí
authors.forename: Pilar
authors.initials: P
authors.lastname: Paredes
authors.forename: Lluis
authors.initials: L
authors.lastname: Mont
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Setoain
authors.forename: Joan
authors.initials: J
authors.lastname: Duch
authors.forename: Silvia
authors.initials: S
authors.lastname: Fuertes
authors.forename: Jaime
authors.initials: J
authors.lastname: Ortín
authors.forename: Ernesto
authors.initials: E
authors.lastname: Diaz-Infante
authors.forename: Francisca
authors.initials: F
authors.lastname: Pons
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003196:Computer Graphics; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000517:prevention & control*