title: Utility of QRS width and echocardiography parameters in an integrative algorithm for selecting heart failure patients with cardiac dyssynchrony.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) is an effective treatment in dilated cardiomyopathy (DCM). However, it has been demonstrated that mechanical dyssynchrony is not related to electrical dyssynchrony. We hypothesized that a new QRS width cutoff could be easier to use as a first step in the selection of patients with inter- and intraventricular dyssynchrony.
  
  
  METHODS
  We included 58 patients with DCM. Electrocardiographic (PR interval and QRS width) and echocardiographic (left ventricular dimensions, systolic and diastolic function, dyssynchrony parameters) data were evaluated in all patients.
  
  
  RESULTS
  According to QRS width, we divided the study population in two groups: Group 1, 25 patients having a narrow QRS (<or=120 ms), and Group 2, 33 patients having a wide QRS (>120 ms). Patients in Group 2 had larger left ventricles, with similar systolic function and more severe diastolic dysfunction than patients with narrow QRS. Interventricular dyssynchrony was more frequent in group 2 (54.5% vs 20%, p=0.01), while intraventricular dyssynchrony was highly prevalent in both groups (82.1% vs 72%, p=0.48). A QRS>140 ms best predicted the presence of interventricular dyssynchrony (sensitivity 78.2% and specificity 63.6%), while a QRS>150 ms best predicts intraventricular dyssynchrony (sensitivity 48.6% and specificity 80%).
  
  
  CONCLUSIONS
  Intraventricular dyssynchrony has a high prevalence in patients with DCM, irrespective of the QRS width. Using a higher QRS width cutoff (150 ms) might help in patient selection for CRT. Electrocardiography and echocardiography can be combined into a selection algorithm for patients receiving resynchronization therapy.
authors.affiliation: Department of Cardiology, Institute of Cardiovascular Diseases Prof.C.C.Iliescu, 258 Fundeni Way, 022328 Bucharest, Romania. rjurcut@gmail.com
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Jurcut
authors.forename: Ioana
authors.initials: I
authors.lastname: Pop
authors.forename: Cosmin
authors.initials: C
authors.lastname: Calin
authors.forename: Ioan Mircea
authors.initials: IM
authors.lastname: Coman
authors.forename: Radu
authors.initials: R
authors.lastname: Ciudin
authors.forename: Carmen
authors.initials: C
authors.lastname: Ginghina