tokens: OBJECTIVES : To assess the added diagnostic value of a new cardiac performance index ( dP / dtejc ) measurement , based on brachial artery flow changes , as compared to standard 12 - lead ECG , for detecting dobutamine - induced myocardial ischemia , using Tc99m-Sestamibi single - photon emission computed tomography as the gold standard of comparison to assess the presence or absence of ischemia .