VARIABILITY OF TIME AND AMPLITUDE ECG INDICATORS IN OLDER ADULTS
The purpose of this article was to determine the effect of the clinostatic test on the electrical propertiesof the myocardium in older adults leading an active lifestyle. Materials and methods. The study involved38 people aged between 70 and 90 years living in a northern city (Syktyvkar, 61°N) and leading an activelifestyle. The indicators of the electrical properties of the cardiac muscle were determined before andafter the clinostatic test. For this purpose, an ECG was recorded in the standard lead II in the standingand lying positions. Results. Using the method of paired comparisons, we showed a decrease in heartrate under the influence of the clinostatic test from 76 ± 10 beats/min to 64 ± 10 beats/min. The variability of ECG components according to pNN50 (the percentage of successive NN intervals differing from each other by more than 50 ms) in older adults in the standing position was, on average, two times lower thanin the lying position. The PP interval increased from 0.81 ± 0.12 s (in the standing position) to 0.90 ± 0.10 s(in the lying position). The PT interval remained practically unchanged, staying at the level of (0.46 ±± 0.07) - (0.49 ± 0.07) s. The TP segment grew from 0.35 to 0.42 ± 0.10 s. The RD amplitude was 1.04 ±± 0.43 mV in the standing and 0.88 ± 0.30 mV in the lying position; the propagation rate of depolarizationin the cardiac muscle was 245 ± 137 and 205 ± 106 mm/s, respectively. In addition, the paper discussedthe mechanism of opposite reactions to the clinostatic test, i.e. increasing duration of cardiointervals anddecreasing amplitude indicators.