FIELD: medicine.SUBSTANCE: group of inventions refers to medicine, namely, to a method and an apparatus for assessing the state of the vessels under each heart contraction, according to the continuous recording of blood pressure (BP) with Penaz method, electrocardiograms and data on local vessel blood filling. Method is carried out by means of two photoplethysmographic signals simultaneously recorded on different fingers of one limb. On one of the fingers, continuous monitoring of the constancy of the vessel blood filling of this finger is carried out with Penaz method and the cuff pressure is recorded as the blood pressure signal in absolute pressure units. Pressure on the other finger is created by the cuff at a constant level, established in the range between systolic and diastolic pressure, recording the photoplethysmographic pulse curve reflecting the blood filling of the finger vessels. Data obtained during the registration of signals is processed mathematically. In the course of mathematical processing of the recorded signals under each heart contraction, the systolic blood pressure values obtained from continuous measurements with Penaz method are compared, and the pressure calculated from the pulse wave velocity (PWV). Discrepancy of values is interpreted as a manifestation of changes in the state of the vasculature, vasodilation or vasoconstriction of vessels of the muscular type, the intensity of which is estimated by the formulas:or, where I– an index of percentage proportions, characterizing the relative divergence of systolic blood pressure values, obtained by measuring with Penaz method and by calculation, by the pulse wave velocity, I– an index of percentage proportions, characterizing the ratio between the values of systolic BP, obtained by measuring with Penaz method and calculated by the pulse wave velocity, P– the value of the measured systolic blood pressure, R– the value of systolic blood pressure, calculated from the speed of the pulse wave. D