FIGURE 4. (A) Determination of threshold value of unipolar endocardial voltage for identification of PET viable myocardium with sensitivity and specificity of 85% based on threshold of 5.2 mV. (B) ROC curves of UpV and LLS for differentiation between PET viable and PET nonviable myocardium with area under the curve of 0.9 ± 0.03 and 0.69 ± 0.06, respectively.