title: Combined longitudinal and radial dyssynchrony predicts ventricular response after resynchronization therapy.
abstract: OBJECTIVE
  The purpose of this study was to test the hypothesis that a combined echocardiographic assessment of longitudinal dyssynchrony by tissue Doppler imaging (TDI) and radial dyssynchrony by speckle-tracking strain may predict left ventricular (LV) functional response to cardiac resynchronization therapy (CRT).
  
  
  BACKGROUND
  Mechanical LV dyssynchrony is associated with response to CRT; however, complex patterns may exist.
  
  
  METHODS
  We studied 190 heart failure patients (ejection fraction [EF] 23 +/- 6%, QRS duration 168 +/- 27 ms) before and after CRT. Longitudinal dyssynchrony was assessed by color TDI for time to peak velocity (2 sites in all and 12 sites in a subgroup of 67). Radial dyssynchrony was assessed by speckle-tracking radial strain. The LV response was defined as > or =15% increase in EF.
  
  
  RESULTS
  One hundred seventy-six patients (93%) had technically sufficient baseline and follow-up data available. Overall, 34% were EF nonresponders at 6 +/- 3 months after CRT. When both longitudinal dyssynchrony by 2-site TDI (> or =60 ms) and radial dyssynchrony (> or =130 ms) were positive, 95% of patients had an EF response; when both were negative, 21% had an EF response (p < 0.001 vs. both positive). The EF response rate was lowest (10%) when dyssynchrony was negative using 12-site TDI and radial strain (p < 0.001 vs. both positive). When either longitudinal or radial dyssynchrony was positive (but not both), 59% had an EF response. Combined longitudinal and radial dyssynchrony predicted EF response with 88% sensitivity and 80% specificity, which was significantly better than either technique alone (p < 0.0001).
  
  
  CONCLUSIONS
  Combined patterns of longitudinal and radial dyssynchrony can be predictive of LV functional response after CRT.
authors.affiliation: Cardiovascular Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15213-2582, USA. gorcsanj@upmc.edu
authors.forename: John
authors.initials: J
authors.lastname: Gorcsan
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanabe
authors.forename: Gabe B
authors.initials: GB
authors.lastname: Bleeker
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Suffoletto
authors.forename: Nini C
authors.initials: NC
authors.lastname: Thomas
authors.forename: Samir
authors.initials: S
authors.lastname: Saba
authors.forename: Laurens F
authors.initials: LF
authors.lastname: Tops
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial; D015150:Echocardiography, Doppler / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D020127:Recovery of Function; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling