PSI - Issue 40

V. Mironov et al. / Procedia Structural Integrity 40 (2022) 296–306 V. Mironov at al. / Structural Integrity Procedia 00 (2022) 000 – 000

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complex influences in SN correspondingly to total spectrum (100 %). These regulative influences determine HRV regulations of the wave structure of RR intervals according to the difference of speeds and frequencies of impulses: 0.0 to 0.033 Hz is a very low frequency domain (VLF) related to humoral-metabolic influence Mironova at al. (2000, 2009), sympathetic regulation is associated with 0.033 to 0.12 Hz (low frequency - LF) domain Kalisnik at al. (2007), Min at al. (2010), Brener at al. (2008); parasympathetic regulation is assessed in a high frequency (HF) domain of 0.12 to 0.24 Hz Zhemaytite at al. (1985), Zhemaytite at al. (1982), Mironov (2002), Lakusic at al. (2009), Dao at al. (2010), Hugh at al. (1997). The share of HF spectral influences is expected to prevail in a healthy person because it is mediated by 3 types of receptors of the pulmonary parenchyma. There are 5 positions of HRV registration, namely: the initial lying position (Ph), the Valsalva-Burker parasympathetic test (Vm), the Ashner humoral test (pA), the active orthostatic test (Aop), and during the exercise test (PWC120) with submaximal load. The stimulant period in every test was different between initial data and in a moment of the maximal reaction to stimuli in tests (ΔRR is maximal reaction to stimul i in test) Mironova at al. (2000, 2009). The RCG of a healthy man is shown in Fig. 1. Cardiac comparisons before and after CABGS are numerous and diverse; they differ from the norm visually in terms of indicators, but each of them has a specific pattern of the HRV wave structure Kalisnik at al. (2007), Min at al. (2010), Brener at al. (2008), Kazemi at al. (2011), Ksela at al. (2009), Laitio at al. (2007), Carney at al. (2005). HRV stabilization is the most often common marker of a high risk of the lethal outcome. It is a syndrome named an autonomic cardioneuropathy (Ewing D., 1978). The mathematical analysis was made out in the SSS-16 program. Also, spectral analysis for the evaluation of a correlation between 3 regulative factors of the heart rate was performed.

Fig. 1. Rhythmocardiograms, a spectrogram, and middle values of RCG signs of a healthy man. 1 – the middle quadratic deviation of the humoral HRV waves; m – the middle quadratic deviation of sympathetic HRV waves; s – the middle quadratic deviation of parasympathetic HRV waves. Spectral correlation of the autonomic and humoral-metabolic influences on the sinoatrial node: VLF% – the share of humoral-metabolic regulation; LF% – the share of sympathetic regulation; HF% – the share of the parasympathetic regulation in total spectrum (l00%). 3. Results and discussion Possibilities of HRV analysis by high-resolution RCG as a method for evaluating the actual cardiovascular status during coronary artery bypass graft surgery (CABGS) in patients with stenocardia were presented. The method was based on the remote computer control and analysis of the peripheral autonomic regulation of the sinoatrial node pacemaker activity before and during stages of CABGS in patients with angina pectoris. The following results were received. Before CABGS, during the selection of patients for cardiosurgical revascularization, additional RCG symptoms for diagnosing angina pectoris were defined. Every stage of CABGS had peculiarities on the rhythmocardiogram correlated to pathophysiologic technology of CABGS, which can be quickly analyzed for the management of operation. RCG data before CABGS consist of HRV predictors of life-threatening