title: Mechanical dyssynchrony after myocardial infarction in patients with left ventricular dysfunction, heart failure, or both.
abstract: BACKGROUND
  Mechanical dyssynchrony is considered an independent predictor for adverse cardiovascular outcomes in patients with heart failure. However, its importance as a risk factor after myocardial infarction is not well defined.
  
  
  RESULTS
  We examined the influence of mechanical dyssynchrony on outcome in patients with left ventricular dysfunction, heart failure, or both after myocardial infarction who were enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) echocardiography study. B-mode speckle tracking with velocity vector imaging was used to assess ventricular synchrony in 381 patients who had image quality sufficient for analysis. Time to regional peak velocity and time to strain rate were measured among 12 left ventricular segments from the apical 4- and 2- chamber views, and the SDs between all 12 segments were used as a measure of dyssynchrony. The relationships between the SD of time to regional peak velocity and strain rate and clinical outcome of death or heart failure were assessed. In a multivariate Cox model adjusted for clinical and echocardiographic variables, the SD of time to peak velocity (hazard ratio per 10 ms, 1.10; 95% confidence interval, 1.02 to 1.18; P=0.010) and the SD of time to strain rate (hazard ratio per 10 ms, 1.16; 95% confidence interval, 1.06 to 1.27; P=0.001) were independent predictors of death or heart failure.
  
  
  CONCLUSIONS
  Left ventricular dyssynchrony is independently associated with increased risk of death or heart failure after myocardial infarction, suggesting that contractile pattern may play a role in post-myocardial infarction prognosis.
authors.affiliation: Cardiovascular Division, Brigham and Women's Hospital, Boston, MA 02115, USA.
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Shin
authors.forename: Chung-Lieh
authors.initials: CL
authors.lastname: Hung
authors.forename: Hajime
authors.initials: H
authors.lastname: Uno
authors.forename: Amira H
authors.initials: AH
authors.lastname: Hassanein
authors.forename: Anil
authors.initials: A
authors.lastname: Verma
authors.forename: Mikhail
authors.initials: M
authors.lastname: Bourgoun
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
authors.forename: Jalal K
authors.initials: JK
authors.lastname: Ghali
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Velazquez
authors.forename: Robert M
authors.initials: RM
authors.lastname: Califf
authors.forename: Marc A
authors.initials: MA
authors.lastname: Pfeffer
authors.forename: Scott D
authors.initials: SD
authors.lastname: Solomon
mesh_terms: D000368:Aged; D000703:Analog-Digital Conversion; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D003643:Death; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000150:complications*; D011379:Prognosis; D016016:Proportional Hazards Models; D013314:Stress, Mechanical; D013777:Tetrazoles / Q000627:therapeutic use; D014463:Ultrasonography; D014633:Valine / Q000031:analogs & derivatives / Q000627:therapeutic use; D000068756:Valsartan; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D014741:Video Recording
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D013777:Tetrazoles; D000068756:Valsartan; D014633:Valine