Efficient utilization of echocardiography for the assessment of left ventricular systolic function

Background We hypothesized that patients could be selected for echocardiogr aphic evaluation of left ventricular (IV) systolic function on the basis of historic, clinical, radiographic, and electrocardiographic criteria. Methods and Results We prospectively evaluated 300 consecutive inpatients r eferred for the echocardiographic assessment of LV function, of whom 124 (4 1%) had LV systolic dysfunction (LVSD) (IV 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 rad iography was the only predictor. Among the electrocardiographic findings, t he presence of left bundle branch block was positively correlated with the presence of LVSD, whereas a normal electrocardiogram was negatively correla ted with this finding. Only 2 patients with LVSD had a normal electrocardio gram. The addition of significant predictors on physical examination and ch est radiography doubled the predictive value of the historic variables for determining LVSD. The addition of electrocardiographic findings further dou bled the predictive valve of the model. Almost 45% of the predictive power of the final multivariate model (chi-square of 48 of the total chi-square o f 108) was based on the absence of normal electrocardiogram in patients wit h LVSD. When chest radiographic findings were excluded from the model, the overall predictive power of the model did not change, with the normal elect rocardiogram gaining greater prominence: Full 56% of the predictive power o f the model (chi-square of 60 of the total chi-square of 108) resided in th e ability of a normal electrocardiogram to discriminate between patients wi th and those without LVSD. Conclusions Historic, chest radiographic, and electrocardiographic variable s can be used to predict low likelihood of LVSD on echocardiography. In par ticular, when the electrocardiogram is normal, it is extremely unlikely to have LVSD. It can be argued that such patients should not be referred for e chocardiography.