PSI - Issue 40

V.A. Mironov et al. / Procedia Structural Integrity 40 (2022) 307–313 V. A. Mironov at al. / Structural Integrity Procedia 00 (2022) 000 – 000

310

4

Table 1. The parameters of the HRV analysis for the control group (n=41, upper line) and for the PCAP patients (n=28, lower line)

Ph , initial background in the supine position

HRV parameters, s and %, (M ±σ)

Vm , Valsalva maneuver 0.904±0.084 0.610±0.008 Z=22.6 0.058±0.010 0.019±0.003 Z=4.2 0.027±0.01 0.010±0.002 Z=11.3 0.026±0.01 0.011±0.003 Z=8.8 0.041±0.012 0.018±0.009 Z=9.5 19.70 ± 9.70 45.28±18.30 Z=14.0 27.17±10.02 12.0 ±5 .5 Z=8.1

Aop , active orthotest 0.770±0.050 0.620±0.011 Z=18.7 0.040±0.010 0.017±0.004 z=13.7 0.023±0.009 0.011±0.008 Z=6.0 0.024±0.008 0.012±0.004 Z=8.5 0.015±0.008 0.008±0.003 Z=5.3 16.6±11.08 52.5 ± 9.7 Z=14.4 42.7±8.3 20.02 ±5. 09 Z=14.0

PWC 120 , exercise tolerance test

pA , Aschner test

RR average interval, s

0.740±0.101 0.685±0.022 Z=3.6 0.048±0.010 0.025±0.003 Z=13.5 0.028±0.010 0.013±0.003 Z=10.0 0.025±0.01 0.01±0.003 Z= 10.0 0.042±0.020 0.018±0.007 Z=8.0 28.6 ± 20.1 45.39±16.6 Z=3.56 24.62±10.5 15.2 ±6. 31 Z=4.36

0.780±0.014 0.620±0.011 Z=8.0 0.055±0.020 0.017±0.004 Z=12.6 0.028±0.010 0.012±0.009 Z=8.0 0.028±0.009 0.050±0.001 Z=11.0 0.036±0.010 0.019±0.020 Z=5.2 19.5 ± 9.5 45.78±10.8 Z=20.9

0.710±0.062 0.550±0.007 Z=4.3 0.043±0.012 0.020±0.011 Z=8.5 0.029±0.001 0.015±0.008 Z=7.0 0.024±0.010 0.011±0.001 Z=8.1 0.047±0.017 0.022±0.010 Z=10.0 39.4 ± 9.5 57.6±12.4 2 Z=6.5

SDNN , standard deviation of all intervals, s σl , rms deviation of humoral metabolic waves, s σm , rms deviation of sympathetic waves, s σs , rms deviation of parasympathetic waves, s

VLF% , spectral share of humoral metabolic effects in SAN

26.5±7.7 18.5 ±2. 5 Z=6.2

27.6±3.1 17.2 ±1. 5 Z=8.3 27.8±9.4 15.1 ± 1.4 Z=8.5

LF% , spectral share of sympathetic regulation

HF% , spectral share of parasympathetic regulation 25.8±18.6 12.8 ± 2.2 Z=4.4 Note: the table uses an analog of the t criterion for nonparametric large samples. The significance of the differences between 1.96 and 2.3 varies from 5% to 1%, respectively. In the initial supine position of all the patients with ischemic heart disease (IHD), the average RR interval was always definitely lower than in the healthy control group. This can be considered compensatory and yet pathologic since this decrease always followed the action of the stimuli in the tests, with subsequent slow restoration of the initial level, irrespective of their autonomic stimulating trends. The range of the standard deviation of all the HRV waves, SDNN, also proved to be definitely lower, and also in all positions, unidirectionally and irrespective of the character of the stimulus in the test and the intensity of its action. For example, when comparing the efficacy of the stimulus in Vm (deep inspiration with breath hold), when the mechanical, irritant, and juxtacapillary receptors of the powerful pulmonary parenchyma are irritated and the parasympathetic effect on the heart contraction activity is reciprocally amplified, i.e., the intervals must increase on average, we recorded a paradoxical reaction, namely decreasing intervals. The same reaction occurred in the Aschner test with a pressor action on the eyeballs. According to our observations, this test amplifies the effect of the humoral metabolic factor on sinus node pacemakers since the action on eyeballs is transmitted through the optic nerve, chiasm, and the Edinger – Westphal nucleus to the anterior cerebral trunk connected with the endocrine system. In the other tests, i.e. active orthostatic and submaximal Aop and PWC 120 there is the same decrease in the amplitude of RR interval fluctuations. Due to what autonomic or humoral effects is it? It is due to sympathetic, parasympathetic, and humoral metabolic effects since a unidirectional reaction was revealed in all positions. That is, the reason for such changes is independent of the regulation factors. It does not testify to the weakening of the most rapid autonomic control; in fact, in the 29.24±9.9 15.1 ± 1.8 Z=9.0 23.06±3.6 15.7 ± 2.0 Z=10.8 40.6±17.5 12.3 ± 2.7 Z=10.2