title: Quantification of left ventricular internal flow from cardiac magnetic resonance images in patients with dyssynchronous heart failure.
abstract: OBJECTIVE
  To develop a method for quantifying left ventricular (LV) internal flow as a measure of dyssynchrony using standard cine cardiac magnetic resonance (CMR) images.
  
  
  METHODS
  CMR images were obtained from 10 healthy controls and 10 patients with dyssynchronous heart failure (class III/IV, LV ejection fraction <35%, pattern seen in an electrocardiogram QRS duration > 150 msec). The LV volume was reconstructed and divided into 16 regions. Internal flow was defined as the sum of the regional volume changes minus the global volume change during each time step in the cardiac cycle. Internal flow fraction (IFF) was defined as the total internal flow as a percentage of stroke volume during systole (IFF(systole)), diastole (IFF(diastole)), or the whole cycle (IFF(whole)).
  
  
  RESULTS
  IFF(whole) was significantly increased in the patients (9.9 +/- 5.0% vs. 1.5 +/- 0.5% in the controls, P < 0.001). An IFF(whole) threshold of 4% discriminated between patients and controls with 90% sensitivity and 100% specificity. IFF(diastole) (2.3 +/- 0.8%) was greater than IFF(systole) (0.8 +/- 0.5%) in the normal controls (P < 0.001) while the patients had similar IFF(diastole) (7.8 +/- 4.2%) and IFF(systole) (12.0 +/- 7.8%).
  
  
  CONCLUSIONS
  Left ventricular internal flow fraction can be quantified from standard CMR images. In this preliminary study, Left ventricular internal flow fraction discriminated patients with dyssynchronous heart failure from normal controls with 95% accuracy.
authors.affiliation: Emory University School of Medicine, Atlanta, Georgia 30322, USA. bfornwa@emory.edu
authors.forename: Brandon K
authors.initials: BK
authors.lastname: Fornwalt
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Gonzales
authors.forename: Jana G
authors.initials: JG
authors.lastname: Delfino
authors.forename: Robert
authors.initials: R
authors.lastname: Eisner
authors.forename: Angel R
authors.initials: AR
authors.lastname: León
authors.forename: John N
authors.initials: JN
authors.lastname: Oshinski
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*