Objective ― This study compares the statistical characteristics of interaction between 0.1 Hz oscillations in heart rate variability (HRV) and photoplethysmographic waveform variability (PPGV) in healthy subjects and patients with myocardial infarction (MI). 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 MI. The 10-minute signals of simultaneously recorded electrocardiogram (ECG) and photoplethysmogram (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 PPGV. Results ― The total percentage of phase synchronization between 0.1 Hz oscillations is significantly greater in healthy subjects than in MI 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 MI patients had greater variance between the basic frequencies of 0.1 Hz oscillations in HRV and PPGV than healthy subjects. This phenomenon correlates with the increased level of phase noises in the records of MI 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.
Vladimir A. Shvartz, Anatoly S. Karavaev, Ekaterina I. Borovkova, Sergey A. Mironov, Vladimir I. Ponomarenko, Mikhail D. Prokhorov, Yurii M. Ishbulatov, Elena E. Lapsheva, Vladimir I. Gridnev, Anton R. Kiselev Investigation of statistical characteristics of interaction between the low-frequency oscillations in heart rate variability and photoplethysmographic waveform variability in healthy subjects and myocardial infarction patients // Russian Open Medical Journal, Vol. 5, Issue 2, 2016, pp. 0-0

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.
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. 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 // Saratov Journal of Medical Scientific Research, Vol. 11, Issue 4, 2015, pp. 537-542

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.
Borovkova E.l., Ishbulatov Yu.M., Mironov S.A. Method of synchronization assessment of rythms in regulatory systems for signal analysis in real time // Saratov Journal of Medical Scientific Research, Vol. 10, Issue 3, 2014, pp. 390-395

The aim of this research is to study of the influence of examination stress on psycho-emotional status and functional state of the cardiovascular system of the 1-st year students of pedagogical high school. Methods – The study involved 105 young men aged 17-18 enrolled in the specialty "Physical Education". The studies were conducted during the period in-between the exams and during the examination session. The psycho-emotional status was determined by the SAN test questionnaire and test and the CH.D. Spielberg test, adapted for Russia by Ju.L. Khanin. The state of CVS autonomic regulation was evaluated by heart rate, blood pressure, endurance ratio, Kerdo index and the adaptive capacities by P.M. Bayevsky. Results – In the absence of exposure to stress in the majority of young men the studied parameters are within normal limits, indicating sufficient adaptive capabilities. A clear correlation between the level of personal anxiety in students and the nature of their reactivity to examination stress was found: the higher the anxiety level in a student is, the more stress resistance decreases and more pronounced changes in the cardiovascular system autonomic regulation appear. The strain of adaptation mechanism was found in a stressful situation in the first-year students with a high level of personal anxiety and satisfactory adaptation – in young men with average and low personal anxiety.
Liliana K. Tokaeva, Svetlana S. Parshina, S.S. Pavlenkovich The psychoemotional status and cardiovascular system functional state of the first-year students under the influence of examination stress // Russian Open Medical Journal, Vol. 1, Issue 3, 2012, pp. 304-0

The purpose of the article is to study the state of cardiovascular system of sportsmen involved in rowing and canoeing, both before and after training. Material et methods: The research has been performed by means of the developed mobile devices that allow non-invasive screening assessment of the potential risk of collapse complications. Results: The article outlines the results of the survey carried out to determine the presence of vagotonic tone with deficient activity supply and abnormal pulse wave that may lead to circulatory collapse in exercise. Conclusion: The technique of pulse wave and vegetative regulation assessment before and after training enables to prevent the circulatory collapse development in stressful physical exertion in sportsmen.
Usanov D.A., Protopopov А.А., SkripalA.V., AveryanovA.P., Kashchavtsev Е.О. State of cardiovascular system during exercise in sportsmen // Saratov Journal of Medical Scientific Research, Vol. 9, Issue 1, 2013, pp. 64-68

The research work provides current understanding of the functional organization of vegetative regulation of cardiovascular system. The basic oscillatory processes in vegetative regulation system have been determined, and the information about their functional properties has been generalized. The most significant oscillatory processes are main heart rhythm, respiration and low-frequency oscillations in vegetative regulation of cardiovascular system. The article considers intersystem interactions involving the vegetative regulation of cardiovascular system
Kiselev A.R., Gridnev V.I. Oscillatory processes in vegetative regulation of cardiovascular system (Review) // Saratov Journal of Medical Scientific Research, Vol. 7, Issue 1, 2011, pp. 34-39

Synchronization between 0.1 Hz oscillations in heart rate and blood pressure is studied and its change during vertical tilt is evaluated in 37 myocardial infarction patients. Two groups of patients are identified with decreased and increased, respectively, synchronization of the studied oscillations as a response to a tilt test. It is shown that assessment of synchronization of 0.1 Hz oscillations as a response to vertical tilt can be used as a guideline for selecting optimal dose of beta-blocker treatment in post-myocardial infarction patients.
Proceedings of World Academy of Science, Engineering and Technology. 2011. Vol. 76. P.367–372.

Synchronization parameters of 0.1-Hz rhythms isolated from the heart rate and the oscillations of the blood volume in microcirculatory vessels were studied in 12 healthy subjects and 32 patients with acute myocardial infarction. Recordings of the electrocardiogram and the pulsogram from the distal phalanx of the index finger, as well as mechanical recording of respiration with the body in a horizontal position, were performed. In patients with myocardial infarction, the recordings were performed during the first three to five days and the third week after the infarction. Synchronization was tested by plotting phase differences and calculating the total percentage of phase synchronization. Synchronization parameters of 0.1-Hz rhythms were high in healthy subjects. In patients with acute myocardial infarction, synchronization of 0.1-Hz rhythms was considerably poorer. The data obtained suggest that the studied 0.1-Hz rhythms are two independent oscillatory processes that are synchronized in healthy subjects. However, this interaction may be disturbed in cardiovascular pathologies, e.g., myocardial infarction.
Human Physiology, 2007, Vol. 33, No. 2, p. 188–193

The aim is the studying of the synchronization between the rhythm with the frequency of 0.1Hz and the two other rhythms (respiration and heartbeat) under different regimes of breathing. Methods: We studied 7 healthy volunteers aged 20-34 years. The ECG and respiratory signals were simultaneously measured in the sitting position. Four experiments were performed. First, the signals were registered during spontaneous respiration and the three other experiments were carried out under paced respiration with fixed-frequency (0.25 and 0.1Hz) and the frequency linearly increasing from 0.05Hz to 0.3Hz. Results: We observed synchronization between the main heart rhythm (HR) and respiration. All subjects demonstrated the presence of several different n:m epoch of synchronization within one record. Studying synchronization between the low frequency (LF) process and respiration we have not revealed any relationship between the degree of synchronization and the intensities of respiratory sinus arrhythmia and LF oscillations as well as in the case of cardiorespiratory synchronization. For the case of breathing with the frequency of 0.25 Hz we obtain the results coinciding qualitatively with those obtained for the above case of spontaneous respiration. The 0.1Hz breathing leads to the resonant increasing of the HR variability amplitude at this frequency and we observe 1:1 phase and frequency synchronization between the HR and respiration during the entire record. Synchronization between the main HR and the LF rhythm also observed under linearly increasing frequency of respiration. Conclusion: We have shown that the three main rhythms in the cardiovascular system can be synchronized with each other. Synchronization between the main HR and the rhythm with the frequency of 0.1Hz is less pronounced than synchronization between each of these rhythms and respiration.
Abstract book of 33rd International Congress on Electrocardiology, Cologne, Germany, June 28th - July 1st, 2006; PS92: p 37

It is generally agreed that 0.1Hz oscillations characterize the basic properties of the autonomic control of functional components of cardiovascular system. Aim. To study the dynamic of 0.1 Hz oscillations synchronization in the heart rhythm and in the vessels of microcirculation under metoprolol intake during three months in patients with old myocardial infarction. Methods. 20 patients with ischemic heart disease who had had myocardial infarction no less then 6 months ago aged 59±12 were involved in the study. Maximal endurable doses of metoprolol (Metocard-Retard and Metocard, Polpharma) were administered to all the probationers. In 14 of them a daily dose was 200mg. In 3 of them a daily dose was 100mg. For the rest it was 50mg. A simultaneous registration of RR-intervals of electrocardiogram and pulsogram from the distal phalanx of a forefinger was carried out in the probationers under tilt test during 10 minutes with the help of multichannel analyzer EEGA-21/26 «Entsefalan-131-03», model 3 produced by «Medicom-MTD», Russia. Records were made before metoprolol administration and after 3 months of the regular drug intake. 0.1 Hz oscillations were singled out by the band-pass filtering of the signals of RR-chains and a pulsogram. The phase of the compared 0.1 Hz rhythms was estimated. A relative time of synchronization was defined. Clinical status of the patients before and after three months of metoprolol intake was assessed. Results. After three months of intake of maximal endurable doses of metoprolol the number of angina attacks was reduced in average from 24±3 to 10±7 (p<0,01) in the group. The number of intaken tablets of nitroglycerin was also reduced reliably (p<0,01). The increase of the relative time of 0.1 Hz-oscillations synchronization in the heart rhythm and in the vessels of microcirculation under three months of Metocard intake was revealed in 7 patients in the supine posture (by 13.4±8%) and in 10 patients in the standing posture (by 16.1±10%). In the other patients the relative time of synchronization decreased by 19.9±6.7% in the supine posture and by 17.3±7.1 in the standing one. Reliable distinctions in the dynamic of the relative time of synchronization depending on the daily dose of Metocard were not revealed. Conclusion. Using of metoprolol raises the relative time of synchronization of the 0.1 Hz rhythms of cardiovascular system in ~35% of patients in the supine posture and in ~50% in the standing one. It reflects a recovery of the autonomic control and functional relations between the heart rhythm and peripheral circulation in ischemic heart disease patients with old myocardial infarction. The decrease of the relative time of synchronization in a part of the patients shows that in these patients, probably, pathological factors take place and their correction is impossible with the help of beta-blockers only. The study confirms a pronounced antianginal effect produced by metoprolol (Metocard, Metocard-Retard) in patients with old myocardial infarction.
Abstract book of International Congress “Hypertension – from Korotkov to present days”, September 15-17, 2005, Saint-Petersburg, Russia: p 42