title: Efficient utilization of echocardiography for the assessment of left ventricular systolic function.
abstract: BACKGROUND
  We hypothesized that patients could be selected for echocardiographic evaluation of left ventricular (LV) systolic function on the basis of historic, clinical, radiographic, and electrocardiographic criteria.
  
  
  RESULTS
  We prospectively evaluated 300 consecutive inpatients referred for the echocardiographic assessment of LV function, of whom 124 (41%) had LV systolic dysfunction (LVSD) (LV ejection fraction <0.45). Among the historic variables, male sex was the only predictor of LVSD, whereas of the abnormal physical and radiographic findings, cardiomegaly on chest radiography was the only predictor. Among the electrocardiographic findings, the presence of left bundle branch block was positively correlated with the presence of LVSD, whereas a normal electrocardiogram was negatively correlated with this finding. Only 2 patients with LVSD had a normal electrocardiogram. The addition of significant predictors on physical examination and chest radiography doubled the predictive value of the historic variables for determining LVSD. The addition of electrocardiographic findings further doubled the predictive value of the model. Almost 45% of the predictive power of the final multivariate model (chi-square of 48 of the total chi-square of 108) was based on the absence of normal electrocardiogram in patients with LVSD. When chest radiographic findings were excluded from the model, the overall predictive power of the model did not change, with the normal electrocardiogram gaining greater prominence: Full 56% of the predictive power of the model (chi-square of 60 of the total chi-square of 108) resided in the ability of a normal electrocardiogram to discriminate between patients with and those without LVSD.
  
  
  CONCLUSIONS
  Historic, chest radiographic, and electrocardiographic variables can be used to predict low likelihood of LVSD on echocardiography. In particular, when the electrocardiogram is normal, it is extremely unlikely to have LVSD. It can be argued that such patients should not be referred for echocardiography.
authors.affiliation: Cardiovascular Division, University of Virginia Medical Center, Charlottesville, VA 22908, USA.
authors.forename: D
authors.initials: D
authors.lastname: Talreja
authors.forename: C
authors.initials: C
authors.lastname: Gruver
authors.forename: J
authors.initials: J
authors.lastname: Sklenar
authors.forename: J
authors.initials: J
authors.lastname: Dent
authors.forename: S
authors.initials: S
authors.lastname: Kaul
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000175:diagnosis; D006332:Cardiomegaly / Q000000981:diagnostic imaging / Q000453:epidemiology; D016009:Chi-Square Distribution; D003661:Decision Support Techniques; D004452:Echocardiography / Q000191:economics / Q000592:standards*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D015994:Incidence; D016013:Likelihood Functions; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018579:Patient Selection; D010808:Physical Examination; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011859:Radiography; D017678:Sex Distribution; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000453:epidemiology; D016277:Ventricular Function, Left / Q000502:physiology*