title: Left ventricular systolic dyssynchrony is a predictor of cardiac remodeling after myocardial infarction.
abstract: OBJECTIVE
  We sought to determine whether early assessment of left ventricular (LV) dyssynchrony by tissue Doppler imaging may predict progressive ventricular enlargement and cardiac dysfunction after acute myocardial infarction (MI).
  
  
  METHODS
  Forty-seven patients (mean age 59.9 +/- 11.6 years) with normal QRS duration underwent tissue Doppler imaging and contrast-enhanced cardiac magnetic resonance imaging (Ce-MRI) at days 2 to 6, 3 months, and at 1 year after the index MI. Systolic dyssynchrony index (Ts-SD) was calculated from 12 LV segments, and infarct size (IS) by Ce-MRI.
  
  
  RESULTS
  The remodeling group (n = 16) (defined as an increase in end-systolic volume > or =10% between 1 year and baseline) had greater initial IS (27.2 +/- 9.6 vs 13.7 +/- 4.1%, P < .001) and Ts-SD (50.9 +/- 12.8 vs 33.6 +/- 7.7 milliseconds, P < .001) than nonremodeling group (n = 31). At 1 year, the remodeling group had progressive increase in Ts-SD and decrease in LV ejection fraction (57.3 +/- 18.5 and 36.0 +/- 7.6%, respectively; both P < .05 vs baseline). Both Ts-SD (odds ratio 1.19 [1.07-1.32], P = .001) and IS (odds ratio 1.65 [1.19-2.29], P = .003) were shown to be independent predictors of progressive LV remodeling. A cutoff value of Ts-SD > or =45 milliseconds predicted LV remodeling at 1 year (sensitivity 90.5%, specificity 90.9%, Area-under-curve 0.907) (P = .0005).
  
  
  CONCLUSIONS
  Left ventricular systolic dyssynchrony is a newly identified predictor of chronic LV remodeling after acute MI, which is independent and incremental to conventional assessment and IS as measured by Ce-MRI.
authors.affiliation: Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Gabriel W
authors.initials: GW
authors.lastname: Yip
authors.forename: Anna K Y
authors.initials: AK
authors.lastname: Chan
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.forename: Wynnie W M
authors.initials: WW
authors.lastname: Lam
authors.forename: Jeffrey W H
authors.initials: JW
authors.lastname: Fung
authors.forename: Joseph Y S
authors.initials: JY
authors.lastname: Chan
authors.forename: John E
authors.initials: JE
authors.lastname: Sanderson
authors.forename: Cheuk-Man
authors.initials: CM
authors.lastname: Yu
mesh_terms: D000368:Aged; D002306:Cardiac Volume / Q000502:physiology; D018618:Echocardiography, Doppler, Color; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020257:Ventricular Remodeling / Q000502:physiology*