The proper management of entropy, or average information content, can be used for increasing the power of a test. In this paper the ST segment depression of the electrocardiogram, associated to stress test, is used as an information source in an approach to determine the probability of coronary disease. After determining a noisy channel entropy equation, expressed in medical terminology, it can be concluded that the simple ON/OFF, 1 mm standard medical criteria can get only the 60% of the easily available information contents of the test. In order to get the remaining information, a q ary criteria should be used, with q=4, q=7 or q=13, instead of the q=2 standard binary criteria. The importance of this approach resides in the fact that in several cases a more involved, invasive, risky and high cost test, like coronary angiography, can be avoided and, in general terms, a better information about coronary disease can be obtained. The above criteria has been validated in more than 110 cases.

The proper management of entropy, or average information content, can be used for increasing the power of a test. In this paper the ST segment depression of the electrocardiogram, associated to stress test, is used as an information source in an approach to determine the probability of coronary disease. After determining a noisy channel entropy equation, expressed in medical terminology, it can be concluded that the simple ON/OFF, 1 mm standard medical criteria can get only the 60% of the easily available information contents of the test. In order to get the remaining information, a q ary criteria should be used, with q=4, q=7 or q=13, instead of the q=2 standard binary criteria. The importance of this approach resides in the fact that in several cases a more involved, invasive, risky and high cost test, like coronary angiography, can be avoided and, in general terms, a better information about coronary disease can be obtained. The above criteria has been validated in more than 110 cases.