title: Prevalence of echocardiographically detected ventricular asynchrony in patients with left ventricular systolic dysfunction.
abstract: OBJECTIVE
  QRS complex width is not an accurate marker of cardiac asynchrony. Our aims were to determine the prevalence of cardiac asynchrony by Doppler echocardiography for patients with left ventricular (LV) dysfunction and to evaluate whether QRS width is a reliable method for detecting asynchrony.
  
  
  METHODS
  In all, 316 consecutive patients with a LV ejection fraction less than 40% from 13 hospitals comprised the study group. Interventricular asynchrony was defined by the interventricular mechanical delay. Intraventricular asynchrony was evaluated using the calculation of the septal-to-posterior wall motion delay, the difference between time from Q wave to LV ejection end, and time from Q wave to the end of the systolic wave of the most delayed basal segment by Doppler tissue imaging, the SD of the time from the Q wave to the end of the systolic wave of 4 basal segments, and the maximum difference in the time from the Q wave to the end of the systolic wave of all 4 basal segments.
  
  
  RESULTS
  Mean age was 62.14 +/- 13.5 years (234 men; 74.1%). Interventricular asynchrony was present in 50 (26.2%) patients in the narrow QRS group and in 57 (55.3%) patients in the prolonged QRS group (P < .001). Intraventricular asynchrony was present in 40 (20.8%) to 136 (72.8%) patients in the narrow QRS group and in 27 (26.2%) to 82 (79.6%) in the prolonged QRS group, depending on the method used.
  
  
  CONCLUSIONS
  Cardiac asynchrony is highly prevalent for patients with LV dysfunction but there is a very poor agreement among the different methods used to detect it. Interventricular asynchrony is more prevalent for patients with prolonged QRS but intraventricular asynchrony is irrespective of the QRS duration. Further studies are needed to evaluate which method is the best to detect cardiac resynchronization therapy responders.
authors.affiliation: Instituto Cardiovascular, Hospital Clínico San Carlos, Madrid, Spain.
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Perez de Isla
authors.forename: Jose
authors.initials: J
authors.lastname: Florit
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Garcia-Fernandez
authors.forename: Arturo
authors.initials: A
authors.lastname: Evangelista
authors.forename: José
authors.initials: J
authors.lastname: Zamorano
mesh_terms: D000328:Adult; D000368:Aged; D015150:Echocardiography, Doppler; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D015995:Prevalence; D011446:Prospective Studies; D013599:Systole / Q000502:physiology; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology