The objective of the present research was to compare the influence of Enalapril and Metoprolol on synchronization of 0.1 Hz-regulation of heart and blood microcirculation. 42 patients aged 49±9 years old with hypertension I, II were included in the study. 0.1 Hz-oscillations in heart rate variability (HRV) and blood microcirculation were registered during the passive orthostatic sign while breathing spontaneously. The duration of each test was 10 minutes. Synchronization was estimated as a phase difference between 0.1 Hz-rhythms in heart rate and in filling of blood microcirculation. Quantitative measures of synchronization were also estimated. In addition frequency values of HRV spectrum in LF- and HF-ranges were assessed. Enalapril and Metoprolol had comparable effect on blood pressure reduction. Treatment with both Enalapril and Metoprolol in patients with significant vegetative dysfunction resulted in repair of functional interaction between 0.1 Hz-regulation of heart and blood microcirculation. Enalapril was preferred in hypertensive patients with prevalence of disorders of vegetative regulation of blood microcirculation. Metoprolol influenced positively on 0,1 Hz-rhythm synchronization in patients with predominance of heart vegetative regulation dysfunction and in patients with sympathicotonia. In patients with hypertension and initially normal level of synchronization of 0.1 Hz-mechanisms treat¬ment with Enalapril or Metoprolol caused functional dissociation. Differentiated approach to the choice of hypertensive therapy should consider individual peculiarities of system vegetative dysfunction. The level of synchronization of 0.1 Hz-rhythms in cardiovascular system should especially be evaluated initially and during the treatment
Saratov Journal of Medical Scientific Research, 2010, vol. 6, iss. 1, p. 61-72.

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

Phase locking of 0.1 Hz oscillations in heart rhythm and filling the vessels of microcirculation is a characteristic of autonomic control responsible for synchronization of cardiovascular system parts such as heart and vessels of microcirculation. Purpose: To study the impact of methoprolol tartrate (“Metocard”, Polpharma) intake on the dynamic of cardiovascular system parts synchronization in patients with coronary artery disease (CAD) who have had myocardial infarction (MI). Methods: 43 patients (24 men and 19 women) aged 63±8 who had MI 6 month ago were involved in the study. Synchronous 10 minutes record of electrocardiogram (ECG) and pulsogram during orthostatic test was performed. The first (initial) record was carried out in 6 month after MI, the second one – after 3 month of methoprolol intake (200 mg per day). The total duration of all lengths of 0,1 Hz rhythms phase locking in RR-chain and in pulsogram was estimated. This index expressed in percents from total record duration was called summary percent of synchronization (Sps, %). Results: All of probationers were divided into two groups according to orthostatic Sps dynamic. 21 probationers who have shown the positive Sps dynamic under methoprolol intake were related to the group A, 16 probationers who have shown the negative Sps dynamic under methoprolol intake were related to the group B (see Table 1 [Tab. 1]; Me (25%; 75%)). Conclusion: Methoprolol intake were associated with the negative orthostatic Sps dynamic in 37,2% of probationers. We considered this phenomenon showing the worsening of adaptative reserve of cardiovascular system parts autonomic control. It is necessary to assess individual dynamic of adaptative reserve of autonomic control under methoprolol intake in CAD patients who have had MI.
Abstract book of 33rd International Congress on Electrocardiology, Cologne, Germany, June 28th - July 1st, 2006; VO4: p 3-4 // Journal of Electrocardiology. - 2007. - Vol. 40. - Iss. 1, Suppl. - P. S74.