Autonomic Regulation Of Cardiac Activity Research Articles

Brain-heart interaction in acute stroke

The article highlights the main pathophysiological mechanisms of cardiovascular disorders in acute cerebral stroke, which include dysfunction of the hypothalamic-pituitary-adrenal axis, disorders of autonomic regulation of cardiac activity, immune response, and deterioration in the cardiovascular system in case of existing structural, organic lesions of the heart and blood vessels, which in turn can exacerbate the development of cerebral damage. Literature data on clinical, electrophysiological, and biochemical changes in the cardiovascular system in stroke are presented, in particular, depending on the area of brain damage. Attention is focused on possible hemodynamic disturbances, electrocardiographic changes in the heart, increased levels of cardiac troponins, brain natriuretic peptide, and C-reactive protein. Complications that arise in this category of patients are of great clinical importance and significantly affect the course of the disease and further prognosis, which requires close attention not only from neurologists but also from doctors of related specialties.

Dynamics of Non-Invasive Risk Factors of Sudden Cardiac Death after Myocardial Revascularization

Background: An attempt was made to study the effect of surgical myocardial revascularization on the processes of electrical myocardium instability underlying the occurrence of life-threatening ventricular arrhythmias, as well as the possibility of its non-invasive assessment by studying heart rate variability (HRV) and heart rate turbulence (HRT), as well as the duration and dispersion of the QT interval. Based only on the presence of viable myocardium, it is often impossible to predict the positive impact of revascularization on a patient’s prognosis, especially with reduced myocardial contractility. Moreover, given the well-studied relationship between myocardial remodeling and neurohormonal activation, non-invasive methods for assessing the autonomic regulation of cardiac activity can provide additional diagnostic information. Along with this, changes in these indicators and their prognostic role in patients with coronary artery disease after revascularization are subjects of discussion. Methods and Results: All patients underwent a comprehensive clinical and biochemical blood test, transthoracic echocardiography, tissue Doppler echocardiography, ultrasound examination of brachiocephalic arteries, selective coronary angio- and ventriculography, as well as Holter monitoring. Results show that a year after the coronary intervention, there was a significant positive trend in the frequency and structure of ventricular arrhythmias (VA). HRV indicators generally did not show significant dynamics. Only an increase in the values of the SDANN and low-frequency power (LFP) indices was noted, indicating a gradual increase in the activity of the sympathetic part of the autonomic nervous system. HRT indicators also did not show significant dynamics. A significant increase was found in the number of patients with no signs of impaired HRT. The average duration of the QT interval decreased significantly. There was also a tendency to shorten the corrected QT interval; however, it was insignificant. In terms of dispersion, both the QT interval and its corrected index, no significant dynamics were recorded in the general group of patients. Conclusion: Our study found that in patients with prior myocardial infarction, after revascularization, significant positive dynamics were recorded in life-threatening ventricular arrhythmias, but were unreliable for the indicators of autonomic regulation of cardiac activity, such as HRV and HRT.

The role of autonomic regulation of cardiac activity in patient with non-obstructive coronary artery disease

The role of autonomic regulation of cardiac activity in patient with non-obstructive coronary artery disease

Capabilities of long-term ECG monitoring in patients with myocardial infarction: the longer, the better?

Background. In modern cardiology, 24-hour electrocardiogram (ECG) monitoring has a high diagnostic value, but this method has a number of disadvantages in detecting episodes of unstable life-threatening arrhythmias. An increase in ECG monitoring duration allows expanding the possibilities of diagnosing life-threatening arrhythmias.Objective. To study the possibilities of long-term ECG monitoring (48–120 hours) in the detection of life-threatening arrhythmic events and parameters of myocardial electrical instability in patients with ST-segment elevation myocardial infarction (STEMI).Design and methods. The study included 71 STEMI patients. All patients from the 4th day of STEMI underwent multi-day ECG monitoring in 3 leads using a telemetric ECG recording complex with an average recording duration of 90.4 ± 30.2 hours. The analysis of episodes of myocardial ischemia, rhythm and conduction disturbances, turbulence and heart rate variability, late ventricular potentials and dispersion of the QT interval within 5 days was carried out.Results. Long-term monitoring allowed detecting high-grade ventricular extrasystoles. Analysis of episodes of myocardial ischemia in the postinfarction period revealed significant differences in the data of 120h-ECG monitoring in comparison with 24h-ECG. Multiday ECG monitoring made it possible to detect dysfunction of the autonomic regulation of cardiac activity in patients 2 times more often.Conclusion. A comprehensive assessment of the possibilities of multi-day ECG monitoring is a promising direction in predicting severe arrhythmias in patients in the postinfarction period.

The effect of regular physical training on heart rate variability in healthy male volunteers

Abstract Funding Acknowledgements Type of funding sources: None. Background The autonomic nervous system's responses are reflected in heart rate variability (HRV). They have a significant role in accompanying the training process, however, assessment of long-term daily HRV indices dynamics is not widely used in sports cardiology. Purpose To determine if there are variations in long-term responses of autonomic regulation of cardiac activity to regular systematic training. Methods In this prospective study, we included 28 healthy men aged 18-19 years who had a repeated 24-hour Ambulatory ECG monitoring between February 2018 and December 2019 (Figure 1). The subjects were in similar working and living conditions. The training regimen consisted of moderate to vigorous physical activity for 270 (SD 40) minutes per week (total 100 weeks of follow-up). The subjects were divided into groups according to the median of changes in assessment results for various types of physical training (Table 1): with the maximum and minimum positive dynamics of physical fitness in endurance (3000m race), speed (100m race), strength (pull-ups on the horizontal bar). 24-hour Holter was performed using a wearable ECG device. HRV parameters at the beginning and at the end of the study in groups with the maximum positive physical fitness dynamics were compared. To assess HRV, the following daily time-domain indices were used: RMSSD (root mean square of successive RR interval differences), pNN50% (percentage of successive RR intervals that differ by more than 50 ms) and SDANN (standard deviation of the averages of the NN intervals in all 5 min segments of the entire recording). Results The initial mean heart rate in groups 1-6 did not differ significantly across repeated heart rate monitoring (Table 1). In group 1, the improvement in endurance exercise performance directly correlated with changes in RMSSD (rs = 0.297, p <0.05) and pNN50% (rs = 0.448, p <0.05). In group 3, increased fitness in short distance running was accompanied by a decrease in the values of the RMSSD (rs = –0.211, p <0.05) and pNN50% (rs = –0.539, p <0.05) and an increase in the values of the SDANN (rs = 0.352, p < 0.05). In group 5, increased fitness in strength exercises was accompanied by a balanced increase in pNN50% (rs = 0.371, p <0.05), RMSSD (rs = 0.347, p <0.05), as well as SDANN (rs = 0.440, p <0,05). In groups 2, 4, 6, there were similar but weaker associations. Conclusion Systematic training is associated with significant changes in the autonomic regulation of heart rate. An increase in fitness in sprint distance running results in a decrease in daily parasympathetic and an increase in sympathetic activity on the heart. Increased fitness in strength exercises is associated with increase in both sympathetic and parasympathetic activity. While an increase in endurance is accompanied by an increase in the activity of the parasympathetic limb of the autonomic nervous system.

Effect of long-term training on heart rate variability, central hemodynamics and physical working capacity in female swimmers with different sports qualifications

The aim of this study was to compare the indices of heart rate variability, central hemodynamics and physical working capacity in female swimmers with different sports qualifications. Materials and methods. The indices of heart rate variability (HRV), central hemodynamics (CH) and physical development (PD) were studied in 44 female swimmers (mean age 15.00 ± 0.36 years, swimming experience – 7.40 ± 0.35 years) depending on their sports qualifications (MSIC, MS, CMS, first- and second-class athletes). To analyze the autonomic regulation of cardiac activity, power spectral and time-domain indices of HRV were used. CH were examined by the method of automated tetrapolar rheography according to W. Kubiček et al. (1970) in Y. T. Pushkar’s et al. modification (1970). Physical working capacity was measured according to the generally accepted technique on a cycling ergometer using the PWC170 submaximal test. The functional state index (FSI) was calculated using the formula patented by authors. Results. Significant differences were found between the indices of HRV, CH and PD in female swimmers with different qualifications. Thus, in the athletes with the MSIC–MS sports qualifications, heart rate was 61.0 ± 3.8 bpm, cardiac index (CI) – 2.978 ± 0.098 L·min-1·m-2 (there was a trend towards the eukinetic type of hemodynamics (TH)), stress index (SI) – 51.16 ± 12.66 relative units (r.u.), PWC170/kg – 16.98 ± 1.22 kgm·min-1·kg-1, FSI – 6.511 ± 0.422 r.u. A decrease in heart rate among them was correlated with a decrease in SI, and an increase in Mo – with a decrease in CI. In female CMS swimmers, heart rate was 61.37 ± 2.83 beats/min-1, CI – 3.021 ± 0.112 l -1min -1·m -2 , a trend towards the predominantly eukinetic TH, SI – 53.73 ± 9.41 r.u., PWC170 /kg– 14.66 ± 0.683 kgm·min-1·kg -1, FSI – 5.683 ± 0.324 r.u. Reduced values of SI and CI were associated with increased values of Mo and PWC170/kg. In first- and second-class female swimmers, heart rate was 63.05 ± 2.22 beats/min, SI – 50.62 ± 6.4 r.u. This group tended to be eytonic and eukinetic. The mean value of the PWC170/kg was 14.19 ± 0.589 kgm·min-1·kg-1 and FSI – 5.953 ± 0.337 r.u. Correlation analysis confirmed the relationship between the decrease in heart rate and CI and the increase in Mo and PWC170/kg. Conclusions. Long-term training in female swimmers at the distance of 50 to 200 meters is accompanied by the significant increase in the PWC170/kg values with qualification improving, 14.19 ± 0.589 kgm·min-1·kg-1, 14.66 ± 0.683 kgm·min-1·kg-1; 16.98 ± 1.22 kgm·min-1·kg-1, respectively, improvements in HRV (decrease in stress index and increase in Mo) and decrease in CI.

How does high-effective atorvastatin therapy affect the autonomic regulation of cardiac activity in STEMI patients

How does high-effective atorvastatin therapy affect the autonomic regulation of cardiac activity in STEMI patients

Clinical efficiency of combined pharmacotherapy of сoronary artery disease associated with postmenopausal osteoporosis

The aim of the study. To evaluate the clinical efficacy of combined pharmacotherapy with alendronate sodium and exogenous L-arginine on the background of basic treatment of patients with coronary artery disease (CAD) associated with postmenopausal osteoporosis (PMOP).Material and methods. A double open, prospective, monocentric clinical study in parallel groups involved 58 women in the postmenopausal period with a diagnosis of coronary artery disease: stable angina pectoris II-III FC, who had PMOP (age 71 (65; 77) years). By the method of block randomization, patients were divided into two groups: 1 group – 27 women who received standard basic therapy; 2 group – 31 women who were prescribed a combination of alendronate sodium and L-arginine hydrochloride according to the scheme on the background of basic treatment. The indices of daily ECG monitoring by Holter, structural and functional state of the heart and blood vessels assessment, levels of biomarkers (osteoprotegerin, osteocalcin, homocysteine, VEGF-A) assessment in patients were obtained at study entry and after 3 months of therapy.Results. According to the results of daily ECG monitoring in the dynamics of treatment in patients of both groups there was a significant decrease in the number of episodes of supraventricular arrhythmia per day (by 11.54% and 34.52%, respectively; p<0.05) and the ratio of LF / HF in active and passive period. In patients of group 2 in contrast to group 1, there was also a significant decrease in the number of episodes of tachycardia per day (1.8 times; p<0.05), an increase in RMSSD (by 74.36%; p<0.05), a decrease in LF (by 54.69%; p<0.05) and an increase in HF (by 73.71%; p<0.05) in both active and passive periods. After 3 months of treatment in patients of the 2nd group showed a significant decrease in the IMC thickness of the right CA by 7.95%, the size of the LP by 16.83% compared to baseline (p<0.05), while the 1st group no significant changes in these indicators were observed. Under the influence of treatment in patients of the 2nd group revealed a significant decrease in the level of VEGF-A (by 25.41%; p<0.05), homocysteine (by 10.72%; p<0.05), osteoprotegerin (2 times ; p<0.05), while in patients of the 1st group there was a significant decrease only in the level of VEGF-A (by 20.09%; p<0.05). In patients of group 2 compared with patients of group 1, after 3 months of treatment there were significantly fewer episodes of ventricular and supraventricular arrhythmias, smaller LF meaning, IMC, LA size and greater HF meaning, probably lower levels of osteocalcin, VEGF-A and osteoprotegerin.Conclusions. The use of combined therapy in patients with coronary artery disease, comorbid with PMOP, contributes to positive changes in the autonomic regulation of cardiac activity, structural adjustment of the heart and vascular endothelium, normalization of the balance of biomarkers of osteoreparation and bone resorption.

The importance of highly effective lipid-lowering therapy with atorvastatin in the normalization of the autonomic regulation of heart rate in patients with STEMI

Abstract Purpose To assess the importance of highly effective lipid-lowering therapy with atorvastatin in the normalization of the autonomic regulation of cardiac activity in patients with myocardial infarction with ST segment elevation (STEMI). Methods The study included 130 patients with STEMI aged 51.3±8.9 years, the majority of males (91%). Inclusion criteria: age from 35 to 70 years, STEMI confirmed by ECG and the level of biomarkers (troponin I, CK-MB), the presence of hemodynamically significant stenosis of a culprit artery according to coronary angiography provided that other coronary arteries are occluded no more than 50%, left main coronary artery - not more than 30%. Exclusion criteria: a history of myocardial infarction, CHF III-IV NYHA, bundle branch block, atrial fibrillation, artificial pacemaker. All patients took atorvastatin at a dose of 40–80 mg/day for 48 weeks after STEMI. As part of a further study at the 7th-9th day and 48 weeks after STEMI, 24-hour ECG monitoring was performed with the Astrocard system. The spectral parameters of heart rate variability (HRV) were evaluated: TotP (ms2), ULF (ms2), VLF (ms2), LF (ms2), HF (ms2), LF / HF. By the 48th week of treatment, patients were divided into groups depending on the achievement of the target level of low density lipoproteins (LDL) of less than 1.4 mmol / l or less than 50% of the initial values: 64 people who reached target values of LDL and formed the group of high-effective lipid-lowering therapy “H”, the group of low effective treatment “L” included 66 patients whose LDL did not meet the recommended level. The groups were matched by gender, age, and anthropometric data. Results In the “H” group, by the 48th week, a pronounced power amplification of all spectral components was obtained. The TotP parameter increased from 13021 (95% CI 10967; 15076) ms2 to 20988 (95% CI 17617; 24358) ms2 (p=0.0001); HF - from 164 (95% CI 105; 222) ms2 to 249 (95% CI 178; 321) ms2 (p=0.003). An increase in the low-frequency components of HRV was observed: an increase in ULF from 10695 (95% CI 8985; 12406) ms2 to 20401 (95% CI 15099; 25703) ms2 (p=0.0001), VLF - from 1473 (95% CI 1212; 1734) ms2 to 1734 (95% CI 1478; 1990) ms2 (p=0.01), LF - from 761 (95% CI 573; 949) ms2 to 909 (95% CI 736; 1082) ms2 (p=0.02). Against the background of an increase in all parameters of the frequency spectrum, the sympathovagal balance coefficient LF / HF decreased from 6.6 (95% CI 5.7; 7.6) to 5.2 (95% CI 4.3; 6.1) ( p=0.004). An analysis of the HRV indicators dynamics in the L group revealed an increase in only the total spectrum power - TotP from 12740 (95% CI 10947; 14533) ms2 to 20195 (95% CI 16619; 23770) ms2. Conclusions Highly effective therapy with atorvastatin in STEMI patients helps to normalize the parameters of the autonomic regulation of heart rate in the post-infarction period due to the increased effects of parasympathetic activity. Funding Acknowledgement Type of funding source: None

Ассоциация укорочения длины теломер с состоянием вегетативной нервной и антиоксидантной систем у пациентов пожилого возраста с церебральным атеросклерозом и сахарным диабетом 2-го типа

Количество теломер, потерянных во время каждого деления клеток, варьируется у разных людей. Предыдущие исследования показали, что увеличение окислительного стресса и хронического воспаления связаны с ускоренным укорочением теломер, однако механизм, лежащий в основе объединения укорочения длины теломер с этими факторами риска, остается гипотетическим. Целью данного исследования было определение взаимосвязи длины теломер с показателями оксидативного стресса и вариабельности ритма сердца у пациентов с церебральным атеросклерозом на разных стадиях, в том числе перенесших ишеми ческий атеротромботический инсульт, а также выявление влияния вышеуказанных факторов на прогноз укорочения длины теломер у данной категории пациентов. Материал и методы. В комплексном клинико-инструментальном исследовании приняли участие 84 пациента с церебральным атеросклерозом (ЦА) 1-3-й степени и сахарным диабетом 2-го типа (СД). Все пациенты проходили общепринятое клиническое, лабораторное и инструментальное обследование (электрокардиография (ЭКГ), МРТ головного мозга). Результаты.Пациенты были разделены на 2 группы в зависимости от относительной длины теломер. Медиана относительной длины теломер составила 2,848. Доля мужчин составила 21,2% в 1-й и 52,0% во 2-й группах. Для выявления связи показателей использовали метод построения логистических моделей регрессии. Установлена статистически значимая положительная связь риска укорочения теломер с индексом вегетативной регуляции ритма сердца (НЧ/ВЧ) и концентрацией тиобарбитурореактивных веществ (TBARs). Выводы. Изменения ВРС и TBARs у пациентов с ЦА и СД связаны с длиной теломер — маркером клеточного старения. Длина теломер может стать ранним маркером ослабления автономной регуляции сердечной деятельности и отражать истинный биологический возраст ВНС.

LABORATORY-INSTRUMENTAL COMPARISONS OF CARDIAC RHYTHM VARIABILITY IN NEWBORNS FOLLOWING HYPOXIA

Summary Introduction. Determination of the state of autonomic regulation of cardiac activity has been widely used in various disorders in neonatal practice. Hypoxia is known to have a significant adverse effect on myocardial function and autonomic cardiac control processes. Early detection of the development of posthypoxic damage to the autonomic nervous regulation of cardiac activity by analyzing the variability of cardiac rhythm and finding its relationship with other characteristics of cardiac rhythm variability (CRV) may be useful for determining the subsequent therapeutic approach for such infants. The aim of the study is to improve early diagnosis of posthypoxic myocardial damage by studying cardiac rhythm variability of (CRV) in newborns following hypoxia and comparing its characteristics with laboratory-instrumental indicators of cardiovascular system. Material and methods. 187 newborns were examined in the early neonatal period. The study involved assessment of medical records, biochemical blood test (AST, ALT, KFK, KFK-MV, LDH, GGTF),daily monitoring of ECG according to Holter (HMEGG) with determination of the main temporal indicators of heart rate variability, Doppler echocardiography (DEchoCG) and statistical processing. Results and discussion. Depending on the Apgar scale at the 1st minute, the children were divided into 2 main groups: newborns with Apgar score less than 6 points which comprised the 1st group (n=132), newborns with Apgar score of 7 points or more were included into the 2nd group (n=55). Depending on the gestational peculiarities at birth, children were subdivided into subgroups of full–term and preterm infants: group 1a (n=15) were full–term infants with hypoxia at birth, group 1b (n=117) were premature newborns with hypoxia at birth, group 2a (n=43) were full– term neonates without hypoxia at birth, group 2b (n=12) were prematurely born without hypoxia at birth. According to HMEGG findings, the mean, mean minimum and mean maximum heart rates were higher in the group of infants who underwent hypoxia, with the highest rates in the group of premature infants. Circadian index scores were lower in the group of newborns who underwent hypoxia, with the lowest in the group of preterm infants. Assessment of correlation dependencies of CRV time parameters with laboratory parameters and DECHOCG parameters showed that SDANN had the highest percentage of relationships with laboratory and instrumental indicators of CVS status. With the parameters of DECHOCG in all groups, rMSSD and pNN50 indicators had the highest number of relationships, which most fully characterized the state of hemodynamics in the group of newborns with existing disorders of adaptation at birth secondary to hypoxic events (group 1) and in the subgroup of premature children (group 1b). SDNN was associated with CPK-MB and gammaglutamyltransferase values, as an indicator of the antioxidant system of body protection in newborns with impaired adaptation at birth following hypoxia, including in the group of premature infants. Conclusions. Prematurely born children who undergo hypoxia have a more pronounced autonomic imbalance in the regulation of cardiac activity. Comprehensive CRV assessment with determination of all parameters characterizing the state of sympathetic and parasympathetic regulation in comparison with biochemical parameters of CVS and DECHOCG will allow to improve the early diagnosis of posthypoxic myocardial injury and to develop further approach of patient management.

RELATIONSHIP BETWEEN INHIBITION CONTROL FACTORS, SUCCESSFUL TRAINING AND HEALTH OF STUDENTS IN THE CONDITIONS OF STRESS LOADS OF THE EDUCATIONAL PROCESS

The aim of the study was to clarify the role of inhibitory control, taking into account the importance of its central and autonomous components in success level of university students. Methods. The study involved 58 students aged 17-21 years. The functions of executive attention control were evaluated on the basis of testing the reaction time during the selection of congruent and incongruent visual stimuli. As an autonomous component of inhibitory control, heart rate variability indices were considered. For self-assessment of health status, the SF-36 questionnaire was used. Results. A connection between student success level and the functions of executive and autonomous control systems has been established. It indicated that faster selection of information and shorter decision making time, but greater tension in autonomic regulation of cardiac activity with increased tone of the sympathetic nervous system corresponded to a higher success level. According to the results of the regression analysis, the success predictors were indicators of the speed of information selection, the functions of the executive attention system and the adequacy of the processes of autonomous regulation, which explain from 10 to 19 % of its variability. According to the SF-36 questionnaire, the best self-esteem of physical health corresponded to a lower heart rate, and mental health - a lower index of autonomic balance, that was, the predominance of the parasympathetic autonomic nervous system. Conclusions. Higher success level corresponded to the best indicators of the central component of inhibitory control - effective selection of information, but with a greater strain of autonomous regulation of cardiac activity. This indicated the need to increase the stress resistance of students with high examination scores and train executive control of attention when success level was low.

Autonomic and endothelial dysfunction with neurocirculatory asthenia in young men of call-up age

Young men of call-up age with neurocirculatory were asthenia were examined for autonomic regulation of cardiac activity and vasodilatory reserve of the arteries. The functional state of the autonomic nervous system (ANS) was studied with the aid of rythmography with analyse of heart rate variability. The following parameters were studied: vegetative regulation type, responsiveness of departments of ANS and autonomic provision of cardiac activity. The type of vegetative regulation was determined by the mean value of RR interval and indication of the heart rate variability (∆RR). Reactivity of parasympathetic and sympathetic divisions of the ANS and autonomic support of cardiac activity were investigated using breathing test. To ensure vegetative dysadaptation cardiac activity includes reaction with low vegetative coverage of both divisions of the ANS and paradoxical reaction in which there is a decrease in ∆RRmax (instead of increase) and an increase in ∆RRmin instead of decrease. These reactions indicate autonomic dysfunction. Vasodilatory reserve of the arteries was investigated using ultrasonography of the brachial artery with compressive sample and determination of endothelium-dependent vasodilation. It was found that in boys with neurocirculatory asthenia vagotonic and sympathetic types of vegetative regulation are often determined by disadaptative vegetative provision of cardiac activity, which is accompanied by endothelial dysfunction with reduced vasodilator reserve of the arteries.

Dose-dependent effect of continuous erythropoietin receptor activator on cardiac autonomic nervous activity and cardiovascular events in patients treated with online hemodiafiltration

The purpose of the work was to determine the effect of continuous erythropoietin receptor activator (CERA) on the autonomic regulation of cardiac activity and cardiovascular events in patients treated with online hemodiafiltration (HDF). Materials and methods. A total of 105 stable chronic HDF patients were included in this prospective observational multicenter study. According to the CERA treatment, the patients were assigned to one of two groups: the 1st group (n = 73) received CERA for at least 6 months and the 2nd one (n = 32) consisted of HDF patients without CERA treatment for at least 6 months. The observational period was 3 years. Results. It was determined that the patients receiving CERA had a more potent dose-dependent activity of the sympathetic autonomic nervous system. The higher the parasympathetic tone predominance, the lower CERA dose was. The odds ratio for developing nonfatal cardiovascular events was 37 times higher in case of CERA more than 125 μg/month (χ 2 = 32.2; P ˂ 0.0001). Conclusions. Thus, the results of this study have provided the preliminary evidence that the sympathetic ANS activity was greater in HDF patients receiving CERA and had a proportional dose-dependent nature. HDF patients with CERA treatment in a dose ≥125 µg/month had a significantly high risk of all cardiovascular events. Individual approach to low-dose CERA treatment in patients with CKD 5 and HDF could significantly reduce the risk of cardiovascular events.

Автономная регуляция сердечной деятельности во время арифметического счета у спортсменов

Автономная регуляция сердечной деятельности во время арифметического счета у спортсменов

CHARACTERISTICS OF CHANGES IN BLOOD PRESSURE AND HEART RHYTHM DISTURBANCES IN PATIENTS WITH METABOLIC SYNDROME

The purpose of this work is to analyze the daily levels of blood pressure and heart rate variability in patients with signs of metabolic syndrome.Materials and methods. In the period from 2013 to 2016, 364 patients of the age from 20 to 80 (200 men and 164 women) with newly diagnosed MS were prospectively examined. Daily ECG monitoring applying the Holter method was performed with the help of Cardiomax system (USA), in compliance with the standard method for diagnosing paroxysmal forms of arrhythmia and stress and painless forms of ischemia. V2, V5 and avF derivations were registered.Results. The maximum daily average values of systolic and diastolic blood pressure recorded in patients of the 61 to 80 age group were the following: systolic BP - 156.9±3.5 mm Hg diastolic BP - 96.2±4.1 mm Hg The heart rate variability analysis showed that the value of circadian index in patients of the third age group was significantly lower (1.14±0.12) than in patients of the first and second groups, amounting to respectively 1.2±0.11 and 1.19±0.13. Besides, we noticed an increase of daytime and night Ps levels (up to 79.0±9.0 and 66.5±4.1 BPM) in patients of the second group compared to the first group, where the values of these indicators were respectively 75.4±8.4 and 60.6±6.2 BPM. Heart rate variability at different times of day depending on age indicate adverse changes in the autonomic regulation of cardiac activity alongside with increasing the age of patients with MS. With the increase of age in patients with Ms, the rate of detecting cardiovascular complications risk factors steadily grows.Conclusion. It is necessary to conduct dynamic monitoring for patients with symptoms of metabolic syndrome in order to identify signs of cardiovascular system state disturbances, blood pressure and heart rate in particular.

Seasonal Variations in Heart Rate Variability as an Indicator of Stress in Free-Ranging Pregnant Przewalski's Horses (E. ferus przewalskii) within the Hortobágy National Park in Hungary.

Background: Ecosystems with seasonal fluctuations in climate and food availability present physiological challenges to resident mammals and may cause “stress.” The two predominant physiological responses to stressors are (1) the activation of the hypothalamic-pituitary-adrenal axis and (2) the modulation of the autonomic nervous system. To date, the primary indicator for “stress” in wildlife- and zoo animal research are glucocorticoid levels. By measuring the autonomic regulation of cardiac activity, particularly the vagal tone, heart rate variability (HRV) is presently emerging as a suitable indicator of “stress” in farm- and domestic animal research.Objective: The aim of this study was to use HRV, a novel method in wildlife research, to assess seasonal patterns of “stress” in a group of free-ranging Przewalski's horses (Equus ferus przewalskii).Methods: Six pregnant Przewalski's horses from one harem within the Hortobágy National Park in Hungary were subjected to the study. We used a dedicated telemetry system consisting of a subcutaneously implanted transmitter and a receiver and storage unit in a collar to record HRV, heart rate (HR), subcutaneous body temperature, and activity throughout a one-year study period—climate data was also collected. We defined “stress” as a decrease in parasympathetic nervous system tone and calculated RMSSD (root mean square of successive differences) as a measure of HRV. Linear mixed effects models with random intercept per individual were used for statistical analysis.Results: HRV and HR varied considerably throughout the year. Similar to temperate ruminants and hibernating mammals, Przewalski's horses experienced lower HR and HRV during winter, when resources are limited indicating decreased metabolic rates coupled with “stress.” In spring, we observed a drop of HRV along with a peak in HR indicating an increase of allostatic load that is most likely associated with increased energy demands during pregnancy and/or seasonal routines such as the adjustment of the gastrointestinal system to better quality diet.Conclusion: Measuring telemetric HRV is a proven method to study undisturbed reactions of wild animals to their changing environment over the long term. Przewalski's horses experience a loss of complexity in cardiovascular dynamics over the winter and particularly during spring, indicating seasonal “stress.”

Features of the cardiovascular system in babies born with different types of intrauterine growth restriction

Based on the data of clinical and anamnestic examination, cardiointervalography, electrocardiography, and Doppler echocardiography, the investigators examined the features of the cardiovascular system in children born by women with compromised somatic and gynecological histories in the outcome of complicated pregnancy. Groups 1 and 2 included 72 and 69 infants with and without fetal growth restriction, respectively. Group 1 comprised Subgroup 1a of 57 infants with asymmetrical intrauterine growth restriction and Subgroup 1b of 15 children with symmetrical one; of them there were 13 and 2 infants with hypoplastic and dysplastic types. Apparently healthy infants born by apparently healthy mothers in the outcome of physiological pregnancies made up Group 3 (n = 25). There is proof that there are significantly important features of autonomic regulation of cardiac activity and morphofunctional characteristics of the heart. The infants with symmetrical intrauterine growth retardation, unlike those with asymmetrical one, were observed to have impaired autonomic regulation of cardiac activity, which was less obvious at birth, deteriorating over time. At birth, the babies had morphological features of the heart and a greater frequency of functioning of fetal communications. Impaired myocardial metabolic processes prevailed within the first month of life and there was a large frequency of changes similar to those in hypertrophic cardiomyopathy by the end of the first half of life. The featuresrevealed in the infants with different types of intrauterine growth restriction require electrocardiographic and ultrasound examinations, a pediatric cardiologist’s consultations at a maternity hospital, and a subsequent personalized follow-up with corrective measures at an outpatient setting.

HEART RATE VARIABILITY, VENTRICULAR LATE POTENTIALS AND HEART RATE TURBULENCE AS INDICATORS OF CORONARY REPERFUSION IN ST SEGMENT ELEVATION MYOCARDIAL INFARCTION

Aim. To evaluate the dynamics of the parameters of autonomic balance and electrical instability of the myocardium depending on the effectiveness of the restoration of coronary blood flow in pharmacoinvasive revascularization in patients with acute ST segment elevation myocardial infarction. Material and methods . The study included 91 patients who underwent effective thrombolytic therapy (TLT) according to the ECG criteria, followed by (3-24 hour later) coronary angiography with percutaneous coronary intervention (PCI). Before and after PCI the telemetric ECG recording was conducted. The dynamics of the temporal and spectral characteristics of heart rate variability (HRV), presence of ventricular late potentials (VLP) and abnormal heart rate turbulence (HRT) were evaluated. Results. The episodes of ST-segment re-elevation by1 mm or more, lasting at least 1 min, and the dynamics of some HRV indices indicated the development of rethrombosis after TLT. The increase in the mean square deviation of normal intervals to 82.5 (64.5; 94) ms, the average value of the standard deviations of normal intervals calculated over 5-minute intervals throughout the entire recording to 37.5 (31.5; 47.5) ms, the total power of the spectrum and the power of high frequency waves, as well as the decrease in the power of ultra-low frequency waves were found after PCI in the group with a rethrombosis of the infarct-related coronary artery. The analysis of VLP in this group showed an increase in duration of the filtered QRS complex after TLT (to 128.7±34.5 ms), and the root mean square value of the last 40 ms of the QRS complex after PCI (to 49±50.3 μV). Pathological deviations of the HRT parameters (especially the onset of turbulence) independently on the absolute values were registered more often in patients with rethrombosis, and abnormal values of both HRT parameters were found only in patients with episodes of unstable coronary blood flow. Conclusion. The results are the indirect evidences of disruption of autonomic regulation of cardiac activity and increased arrhythmic readiness of myocardium in developing rethrombosis of coronary artery. The pronounced reperfusion injury of the myocardium evidently plays an important role in this process and is associated with embolization of the vessels of the microcirculatory bed, release of free radicals and alteration of cardiomyocytes, especially due to prolonged ischemia.

Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing mental stress

Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing mental stress