FIELD: medicine, in particular, cardiology. SUBSTANCE: bicycle ergometric test with an electrocardiographic monitoring is carried out, in the process of this test rhythmograms are recorded and the obtained data are processed to obtain an index characterizing the patient's functional state. Recording of rhythmograms is limited by rhythmograms at rest and in the stages of 25- and 50-W loads, according to which the spectral density of the power of cardiac rhythm variability is determined within 0.04 to 0.20 Hz. The maximum of the spectral density of the power within the given frequency range and the mean spectral density of the power in the upper values of the frequency range are determined, if the first value exceeds the second one by several times, and if the maximum of the spectral density of power is within a frequency range from 0.08 to 0.14, it is considered to be a characterizing index of diagnosis of myocardial ischemia. If the mentioned index is present in the spectrum of cardiac rhythm variability of the patient both at rest and at 25- and 50-W loads, the obtained negative result of the bicycle ergometric test is considered to be corresponding to the actual clinical status of the patient of myocardial ischemia. If the index is present or absent in the spectrum of cardiac rhythm variability of the patient at rest and is absent at a load, the obtained negative result of the bicycle ergometric test is not considered to be corresponding to the actual clinical status of the patient. If the index is present in the spectrum of patient's cardiac rhythm variability at rest and is absent at a 25-W load, the probability of a false negative result of the bicycle ergometric test is considered to be a mean one, and diagnosis is continued by other methods of examination. The accuracy of diagnosis is judged at an excess of the maximum value of the spectral density of power over the mean spectral density by two times, and rhythmograms are processed by the parametric method of calculation of the spectrum power density on the basis of autoregressive model. EFFECT: enhanced accuracy of estimate. 3 cl, 2 dwg, 2 ex
