PSI - Issue 65

Mironov V.A. et al. / Procedia Structural Integrity 65 (2024) 147–151 Author name / Structural Integrity Procedia 00 (2024) 000–000

149

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Table 1. Values of HRV at rest and vegetative reactivity samples before surgery and during TE

No HRV indicators (M±σ) in seconds and %

Before the operation (top row) and during the operation (bottom row)

p<0,05 (z=2,23)

1

RR – the average systolic interval, second

0.854±0.084 0.847±0.210 z1 = 0.08 30.014 ±0.005 0.009±0.007 z1=1.34 0.018 ±0.011 0.007±0.003 z1 =2.43 0.009±0.004 0.008±0.007 z1 =0.44 0.003±0.002 0.003±0.001 z1 =0.43 0.008±0.005 0.003±0.001 z1 =2.36 49.50±30.45 75.03±15.19 z1 =1.84 6.25±5.84 13.73±11.50 z1 =1.37 544.24±37.93 11.23±5.13 z1 =2.23

> 0.05

2

SDNN – the average deviation of all RR intervals, second

> 0.05

3

ARA – the amplitude of the respiratory arrhythmia, second

<0.05

4

σl – the standard deviation of humoral-metabolic waves, second

> 0.05

5

σm – the standard deviation of sympathetic waves, second

> 0.05

6

σs – the standard deviation of parasympathetic waves, second

<0.05

7

VLF% spectral fraction of humoral-metabolic waves

> 0.05

8

LF% spectral fraction of sympathetic waves

> 0.05

9

HF% spectral fraction of parasympathetic waves

<0.05

During surgical manipulations, the greatest effect was recorded near the recurrent branch of the vagus nerve. This effect manifested itself in the form of rhythm reduction episodes (Fig.1) at the background of high-frequency waves. These waves are characteristic of increased vagal influence on heart rate regulation, which was the basis for changing the localization of the intervention. Fig. 1, 2 illustrates that upon contact with the recurrent nerve during the allocation of the thyroid lobe stump for removal against the background of predominant low-frequency wave formation, increased humoral-metabolic effect on the regulation of heart rhythm, an episode of decreased rhythm of vagal origin was recorded. When the intervention tactics were changed, the episode stopped. Changes in the graphic RCG were preserved intraoperatively in all patients upon contact with RNB. Thus, the registration of excessive vagal influence in direct contact with the recurrent branch of the vagus nerve in patients with NFTG during thyroidectomy was established – Gagiev et al. (2021).