Background:Coronary artery disease (CAD) is associated with a small but measurable amount of electrical disorganization, which may appear as temporal electrical heterogeneity on the electrocardiogram and is not visible with the low resolution, 12‐lead electrocardiogram. A newly developed, multilead, high‐fidelity variance cardiograph captures the heterogeneity component of the electrocardiograph signal. The subsequent analysis produces an electrical heterogeneity index (EHI) by quantifying phase‐invariant electrical disorganization, which represents cardiac abnormalities that are modulated onto the measured high frequency electrocardiogram. A prospective investigation was conducted to determine the predictive accuracy of the variance cardiograph to detect clinically important CAD.Methods:Sixty‐five patients (group I) with documented CAD were given the variance cardiography test, as well as 21 normal volunteers (group II). An EHI>; 75 from the variance cardiograph was determined to best represent a positive test for clinically important CAD.Results:Group I had a mean EHI of 89.5 ± 19.7, while group II had a mean EHI of 61.1 ± 19.1 (P<0.001). The variance cardiograph had a sensitivity of 79%, a specificity of 76%, a positive predictive value of 91%, and a negative predictive value of 55%.Conclusions:These results demonstrate that analysis of the temporal electrical heterogeneity component of the electrocardiographic signal obtained by the variance cardiograph provides a new and reliable stress‐free test For the detec