title: Mechanical dyssynchrony assessed by tissue Doppler imaging is a powerful predictor of mortality in congestive heart failure with normal QRS duration.
abstract: OBJECTIVE
  We sought to test whether the mechanical dyssynchrony assessed by tissue Doppler imaging (TDI) is a predictor of cardiac events in patients with congestive heart failure (CHF) and QRS duration < or =120 ms.
  
  
  BACKGROUND
  The prevalence and prognostic value of mechanical dyssynchrony in patients with CHF and normal QRS duration have not been well clarified.
  
  
  METHODS
  A total of 106 patients (age 63 +/- 11 years) with CHF and ejection fraction (EF) <35% were followed serially; TDI was performed using four basal and four mid-left ventricular segments to assess the time to peak systolic point from R-wave on electrocardiogram (Ts). The standard deviation of Ts (Ts-SD) and the maximal temporal difference of Ts (Ts-diff) of eight segments were used as an indicator of mechanical dyssynchrony. Clinical events included readmission due to worsening of CHF, cardiac transplantation, and death.
  
  
  RESULTS
  After 17 +/- 11 months of follow-up, the clinical event rate was 33% including all-cause mortality of 19%. Prolonged Ts-SD (>37 ms) and Ts-diff (>91 ms) were associated with a significant increase in all clinical events. By multivariate analysis, Ts-diff (>91 ms) was an independent risk factor of clinical events and mortality regardless of age, EF, QRS duration, and use of beta-blocking agents. Mean event-free survival was 16.3 months (95% confidence interval [CI] 11.9 to 20.7) in patients with Ts-diff >91 ms and 31.6 months (95% CI 28.0 to 35.1) in those with Ts-diff < or =91 ms, respectively (p < 0.001).
  
  
  CONCLUSIONS
  Myocardial dyssynchrony assessed by TDI is a powerful predictor of clinical events in CHF with normal QRS.
authors.affiliation: Division of Cardiology, Hangang Sacred Heart Hospital, University of Hallym, Seoul, Korea. cardioch@medimail.co.kr
authors.forename: Goo-Yeong
authors.initials: GY
authors.lastname: Cho
authors.forename: Jae-Kwan
authors.initials: JK
authors.lastname: Song
authors.forename: Woo-Jung
authors.initials: WJ
authors.lastname: Park
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Han
authors.forename: Seung-Hyuk
authors.initials: SH
authors.lastname: Choi
authors.forename: Young-Cheoul
authors.initials: YC
authors.lastname: Doo
authors.forename: Dong-Jin
authors.initials: DJ
authors.lastname: Oh
authors.forename: Yung
authors.initials: Y
authors.lastname: Lee
mesh_terms: D000368:Aged; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016019:Survival Analysis; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality* / Q000503:physiopathology