UTILITY OF THE 12-LEAD ELECTROCARDIOGRAM IN IDENTIFYING UNDERLYING CORONARY-ARTERY DISEASE IN PATIENTS WITH DEPRESSED LEFT-VENTRICULAR SYSTOLIC FUNCTION

We assessed the utility of the 12-lead electrocardiogram (EGG) in iden tifying severe coronary artery disease (CAD) in patients with depresse d left ventricular (LV) systolic function. In 336 patients referred fo r cardiac catheterization with LV ejection fractions <0.50, we compare d the 12-lead ECG of those with and without CAD by multivariate analys is. The sensitivities, specificities, and positive and negative predic tive values of all dichotomous electrocardiographic variables for iden tifying the presence of severe CAD were determined. In comparison to s ubjects with CAD, those without disease were more likely to exhibit le ft-axis deviation (p=0.01), left bundle branch block (p<0.001), or LV hypertrophy (p<0.001), and less likely to exhibit pathologic inferior Q waves (p<0.001). The presence of anterior or any Q waves was similar between the groups. The presence of any diagnostic Q wave had a posit ive predictive value of 92%, sensitivity of 57%, and specificity of 80 % for identifying severe CAD. In patients with LV systolic dysfunction , the 12-lead ECG is insensitive and nonspecific for identifying those with concomitant severe CAD.