[Study of the variations in cardiovascular system indicators using the main component method]

The main component method was used to analyze measurements of cardiovascular parameters taken in 14 healthy operators at rest. The entire sample included 237 observations. Each observation was characterized by the deviation of heart rate, mean blood pressure and stroke volume from individual data points. The latter were individual mean values of the above parameters recorded during the Valsalva maneuver. The first two main components were responsible for over 77% of total variance of signs. Visual analysis of observation distribution with respect to the components revealed small group and single data points situated peripherally at a distance from the major constellation of data points. With respect to the values in these groups it can be assumed that some of them correspond to the stressed state of the cardiovascular system. Two thirds of data points in the stressed groups are associated with the subjects who show a weak reaction to the Valsalva maneuver and one third corresponds to the true stressed state. Taking into account the Valsalva maneuver, the deviations from individual data points can be used to identify the stressed state of the cardiovascular system in healthy men at rest.