Saratov JOURNAL of Medical and Scientific Research

Mironov S.A.

Ministry of Defense of the RF, State Institute for Advanced Training of Physicians, Department of Therapy

Low-frequency skin microvascular oscillations: dynamics, synchronization and compliance with changes in vascular tone during the tilt test

Year: 2019, volume 15 Issue: №3 Pages: 783-790
Heading: Cardiology Article type: Original article
Authors: Mironov S.A., Kiselev A.R., Simonyan M.A., Shvartz V.A., Karavaev A.S., Borovkova E.l., Ishbulatov Yu.M., Popova Yu.V., Posnenkova O.M., Gridnev V.I.
Organization: Central Clinical Military Hospital (Moscow), Saratov State Medical University
Summary:

The purpose is to study the dynamics of low-frequency oscillations (LF; basic frequency of about 0.1 Hz) in the spectra of fingerprint photoplethysmograms (PPG), their synchronization with a similar LF-rhythm in cardiointervalo-gram (CIG) and compliance with changes in vascular tone during the tilt test in healthy volunteers. Material and Methods. Synchronous cardiointerval recording, breathing recording, left shoulder rheovasography and PPG records from the palm surfaces of distal phalanges of anonymous fingers were analyzed, as well as central hemodynamics data by impedance rheocardiography in 30 healthy volunteers during the tilt test. Dynamics of LF-oscillations in PPG signals, their interaction (including synchronization) with similar oscillations in CIG and vascular tone parameters were studied. Results. At the stages of tilt test the values of LF-oscillations power in the spectra of PPG had no statistically significant differences. During the tilt test the index of synchronization of LF-oscillations increased (p<0.01). No correlations were found between the power of LF-oscillations in PPG spectra and vascular tone parameters. Conclusion. Absence of significant changes in LF-oscillations power in PPG spectra in the group of healthy volunteers at the stages of tilt test does not correspond to the dynamics of vascular tone parameters, estimated according to rheography data. At the same time, increased interaction between the autonomic regulation subsystems (heart rhythm — distal blood flow) was observed and resulted in the increase of of LF-oscillations synchronization.

Investigation of statistical characteristics of interaction between the low-frequency oscillations in heart rate variability and peripheral microcirculation in healthy subjects and myocardial infarction patients

Year: 2015, volume 11 Issue: №4 Pages: 537-542
Heading: cardiac surgery Article type: Original article
Authors: Shvartz V.A., Karavaev A.S., Borovkova E.l., Mironov S.A., Ponomarenko V.I., Prokhorov M.D., Butenko A.A., Gridnev V.I., Kiselev A.R.
Organization: Saratov state university, Saratov Institute of Cardiology, Russia, Saratov Branch of Institute of Radio Engineering and Electronics n.a. V.A. Kotelnikov, Bakulev Center of Cardiovascular Surgery
Summary:

Objective. This study compares the statistical characteristics of interaction between 0.1 Hz oscillations in heart rate variability (HRV) and photoplethysmogram (PPG) in healthy subjects and myocardial infarction (Ml) patients. Material and methods. We studied 23 healthy subjects (20 men and 3 women aged 26±3 years) and 23 patients (12 men and 11 women aged 52±4 years) at about one month after Ml. The 10-minute signals of simultaneously recorded cardioin-tervalogram (CIG) and PPG were studied. We calculated the total percentage of phase synchronization between the studied 0.1 Hz oscillations and estimated the distribution functions of duration of synchronous and non-synchronous epochs, the variability of basic frequency of oscillations, and variance of phase noises in 0.1 Hz oscillations in HRV and PPG. Results. The total percentage of phase synchronization between 0.1 Hz oscillations is significantly greater in healthy subjects than in Ml patients (47±3% and 26±4%, respectively). Significant difference between these two groups in the distribution of duration of synchronous and non-synchronous epochs was not revealed. The Ml patients had greater variance between the basic frequencies of 0.1 Hz oscillations in HRV and PPG than healthy subjects. This phenomenon correlates with the increased level of phase noises in the records of Ml patients. Conclusion. The quality of synchronization between 0.1 Hz oscillations in HRV and PPG is associated with the strength of influence of external factors (noises) and variability of the basic frequency of these oscillations.

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Method of synchronization assessment of rythms in regulatory systems for signal analysis in real time

Summary:

A method is proposed for quantitative assessment of the phase synchronization of 0.1 Hz oscillations in autonomic cardiovascular control by photoplethysmogram analysis in real time. The efficiency of the method is shown in the comparison with the results obtained by the previously developed method.

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Functional Diagnostics Methods Comparative Assessment In Determination Of Different Diastolic Dysfunction Types

Year: 2009, volume 5 Issue: №2 Pages: 207-211
Heading: Internal Diseases Article type: Original article
Authors: S.A. Mironov
Organization: Ministry of Defense of the RF, State Institute for Advanced Training of Physicians
Summary:

Analysis of transmitral flow criteria has been used to underestimate diastolic dysfunction degree. The study goal was to compare the evaluation of different echocardiographic methods to determine diastolic dysfunction types. There were 120 patients with chronic cardiac insufficiency under the study; control group included 30 healthy individuals. Pulmonary venous flow, transmitral flow at rest in carrying out Valsalva test and tests with isometric exercise have been examined for verification of diastolic dysfunction type by Impulse Doppler Echocardiographic Method. The findings have been compared with the results of Tissue Doppler Echocardiography.
Among patients with diastolic dysfunction type I according to the transmitral flow examination there were 22 (34%) with diastolic dysfunction type II using Tissue Doppler Echocardiographic method. Besides, 6 persons with diastolic dysfunction type III demonstrated no diastolic dysfunction signs according to the transmitral flow data. The Valsalva test enabled differentiation of diastolic dysfunction type II in only 39% of all cases while test standardization increased the method’s value up to 55%. The isometric exercise test for diastolic reserve indication may be compared by its effectiveness with Tissue Doppler Echocardiographic method used for detection the diastolic dysfunction restrictive types.

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