title: Utility of Equilibrium Radionuclide Angiogram-Derived Measures of Dyssynchrony to Predict Outcomes in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy.
abstract: We evaluated a novel scintigraphic method using new parameters of mechanical left ventricular (LV) dyssynchrony and correlated it with clinical outcomes in heart failure patients with reduced ejection fraction receiving cardiac resynchronization therapy (CRT).
  
  
  METHODS
  Sixty-six advanced heart failure patients referred for CRT with an LV ejection fraction (EF) of < 35% and QRS ≥ 120 ms were studied. We performed equilibrium radionuclide angiography (ERNA) before and 6 mo after CRT. We assessed ventricular dyssynchrony with parameters derived from the first harmonic phase (Ø) analysis of the ERNA time-activity curve and evaluated change in these parameters after 6 mo of CRT. These parameters include novel indices of synchrony (S), a measure of intraventricular contraction order, and entropy (E), a measure of intraventricular contraction disorder, and interventricular synchrony (IVS), a measure of synchronous biventricular function.
  
  
  RESULTS
  Forty-seven (71%) patients improved clinically (responders) at 6 mo after CRT whereas 19 (28.8%) showed no change in New York Heart Association class or worsened (nonresponders). The post-CRT changes in QRS duration (P = 0.006), echocardiographic (P = 0.03) and ERNA LVEF (P = 0.0007), LVS (P = 0.004), LVE (P = 0.006), LV standard deviation of ventricular phase (LVSDØ) (P = 0.004), and IVS (P = 0.05) were significantly different between responders and nonresponders. Sixty-two percent of responders had either an LVS < 0.84 or an IVS ≥ 18.8° as opposed to only 16% of nonresponders (P = 0.001). Twenty-nine of 32 (91%) patients with either of these measures responded to CRT (P < 0.01).
  
  
  CONCLUSIONS
  LVS and IVS are novel measures of LV dyssynchrony derived from ERNA planar analysis. A baseline value of LVS < 0.84 or IVS ≥ 18.8° predicts a positive response to CRT.
authors.affiliation: Section of Nuclear Medicine and Medicine, Cardiovascular Division, Department of Radiology, University of California San Francisco (UCSF), San Francisco, California Nitish.Badhwar@ucsf.edu.
authors.forename: Nitish
authors.initials: N
authors.lastname: Badhwar
authors.affiliation: Section of Nuclear Medicine and Medicine, Cardiovascular Division, Department of Radiology, University of California San Francisco (UCSF), San Francisco, California.
authors.forename: Jameze
authors.initials: J
authors.lastname: James
authors.affiliation: Section of Nuclear Medicine and Medicine, Cardiovascular Division, Department of Radiology, University of California San Francisco (UCSF), San Francisco, California.
authors.forename: Kurt S
authors.initials: KS
authors.lastname: Hoffmayer
authors.affiliation: Section of Nuclear Medicine and Medicine, Cardiovascular Division, Department of Radiology, University of California San Francisco (UCSF), San Francisco, California.
authors.forename: John W
authors.initials: JW
authors.lastname: O'Connell
authors.affiliation: Section of Nuclear Medicine and Medicine, Cardiovascular Division, Department of Radiology, University of California San Francisco (UCSF), San Francisco, California.
authors.forename: Deanna
authors.initials: D
authors.lastname: Green
authors.affiliation: Section of Nuclear Medicine and Medicine, Cardiovascular Division, Department of Radiology, University of California San Francisco (UCSF), San Francisco, California.
authors.forename: Teresa
authors.initials: T
authors.lastname: De Marco
authors.affiliation: Section of Nuclear Medicine and Medicine, Cardiovascular Division, Department of Radiology, University of California San Francisco (UCSF), San Francisco, California.
authors.forename: Elias H
authors.initials: EH
authors.lastname: Botvinick
mesh_terms: D058406:Cardiac Resynchronization Therapy; D005260:Female; D015637:Gated Blood-Pool Imaging; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging
keywords: heart failure; radionuclide angiography; resynchronization therapy; synchrony