Early Diagnosis of Problems Related to the Self-Organization of the Cardiovascular System Based on the Interplay between RR and JT Cardiac Intervals.

The dynamics of the collapse of complexity observable in the performance of the cardiovascular system during the stress test is investigated in this paper. For this purpose, the interplay between the RR and JT cardiac intervals is measured and assessed for each participant. This case study involves a modest sample size of eight individuals with normal and elevated blood pressure. Although it is anticipated that the interaction between the RR and JT intervals is rather complex during the stress test, the existence of interpretable time delays between those cardiac intervals is demonstrated using the time delayed patterns algorithm. The assessment of the cardiovascular mobilization taking place during the stress test is also an integral part of this study. The velocity of adaptation index Ad and the newly formulated modified adaptation index Ar (computed only for the recovery phase) are used to quantify the healthy mobilization of the cardiovascular system for each participant. The time frequency analysis of the difference signal between the RR and JT intervals is used to quantify the collapse of complexity around the load termination point. Finally, a semi-gauge indication tool is constructed to assess the overall goodness of the self-organization of the cardiovascular system during the stress test.

The Mathematical Characterization of the Complexity Matching during a Healing Circle Meditation.

The aim of the study is to evaluate the complexity matching between the HRVs of the group of Healers and the Healee during the various stages of the meditation protocol by employing a novel mathematical approach based on the H-rank algorithm. The complexity matching of heart rate variability is assessed before and during a heart-focused meditation in a close non-contact healing exercise. The experiment was conducted on a group of individuals (eight Healers and one Healee) throughout the various phases of the protocol over a ~75-minute period. The HRV signal for the cohort of individuals was recorded using high resolution HRV recorders with internal clocks for time synchronization. The Hankel transform (H-rank) approach was employed to reconstruct the real-world complex time series in order to measure the algebraic complexity of the heart rate variability and to assess the complexity matching between the reconstructed H-rank of the Healers and Healee during the different phases of the protocol. The integration of the embedding attractor technique was used to aid in the visualization of reconstructed H-rank in state space across the various phases. The findings demonstrate the changes in the degree of reconstructed H-rank (between the Healers and the Healee) during the heart-focused meditation healing phase by employing mathematically anticipated and validated algorithms. It is natural and thought-provoking to contemplate the mechanisms causing the complexity of the reconstructed H-rank to come closer; it can be explicitly stated that the purpose of the study is to communicate a clear idea that the H-rank algorithm is capable of registering subtle changes in the healing process, and that there was no intention of delving deep to uncover the mechanisms involved in the HRV matching. Therefore, the latter might be a distinct goal of future research.

Detection of Atrial Fibrillation Episodes based on 3D Algebraic Relationships between Cardiac Intervals.

In this study, the notion of perfect matrices of Lagrange differences is employed to detect atrial fibrillation episodes based on three ECG parameters (JT interval, QRS interval, RR interval). The case study comprised 8 healthy individuals and 7 unhealthy individuals, and the mean and standard deviation of age was 65.84 ± 1.4 years, height was 1.75 ± 0.12 m, and weight was 79.4 ± 0.9 kg. Initially, it was demonstrated that the sensitivity of algebraic relationships between cardiac intervals increases when the dimension of the perfect matrices of Lagrange differences is extended from two to three. The baseline dataset was established using statistical algorithms for classification by means of the developed decision support system. The classification helps to determine whether the new incoming candidate has indications of atrial fibrillation or not. The application of probability distribution graphs and semi-gauge indicator techniques aided in visualizing the categorization of the new candidates. Though the study's data are limited, this work provides a strong foundation for (1) validating the sensitivity of the perfect matrices of Lagrange differences, (2) establishing a robust baseline dataset for supervised classification, and (3) classifying new incoming candidates within the classification framework. From a clinical standpoint, the developed approach assists in the early detection of atrial fibrillation in an individual.

The Complexity of the Arterial Blood Pressure Regulation during the Stress Test.

In this study, two categories of persons with normal and high ABP are subjected to the bicycle stress test (9 persons with normal ABP and 10 persons with high ABP). All persons are physically active men but not professional sportsmen. The mean and the standard deviation of age is 41.11 ± 10.21 years; height 178.88 ± 0.071 m; weight 80.53 ± 10.01 kg; body mass index 25.10 ± 2.06 kg/m2. Machine learning algorithms are employed to build a set of rules for the classification of the performance during the stress test. The heart rate, the JT interval, and the blood pressure readings are observed during the load and the recovery phases of the exercise. Although it is obvious that the two groups of persons will behave differently throughout the bicycle stress test, with this novel study, we are able to detect subtle variations in the rate at which these changes occur. This paper proves that these differences are measurable and substantial to detect subtle differences in the self-organization of the human cardiovascular system. It is shown that the data collected during the load phase of the stress test plays a more significant role than the data collected during the recovery phase. The data collected from the two groups of persons are approximated by Gaussian distribution. The introduced classification algorithm based on the statistical analysis and the triangle coordinate system helps to determine whether the reaction of the cardiovascular system of a new candidate is more pronounced by an increased heart rate or an increased blood pressure during the stress test. The developed approach produces valuable information about the self-organization of human cardiovascular system during a physical exercise.

Visualization of Complex Processes in Cardiovascular System during Electrical Auricular Vagus Nerve Stimulation.

The analysis of human physiological systems from the point of view of complex systems theory remains a very ambitious task. The complexity of the problem often encourages the use of innovative mathematical methods analyzing the processes that take place in space and time. The main goal of this paper is to visualize the cardiovascular system during auricular vagus nerve stimulation (aVNS) using the matrix differences to evaluate the dynamic signal interfaces by cointegrating the initial signal data into the matrices during each case. Algebraic relationships between RR/JT and JT/QRS cardiac intervals are used not only to track the cardiovascular changes during aVNS but also to characterize individual features of the person during the transit through the therapy. This paper presents the computational techniques that can visualize the complex dynamical processes taking place in the cardiovascular system using the electrical aVNS therapy. Four healthy volunteers participated in two verum and two placebo experiments. We discovered that the body's reaction to the stimulation was very different in each of the cases, but the presented techniques opened new possibilities for a novel interpretation of the dynamics of the cardiovascular system.

Yoga's Effects on the Cardiovascular System of Healthy Women: Implications for Best Practices.

CONTEXT: Yoga as a form of physical activity is growing in popularity. During yoga, individuals interrupt the stress response, which is typically associated with high blood pressure (BP), impaired focus, and high levels of anxiety. Consequently, research into yoga's effects on stress should place a special emphasis upon the interplay of the nervous and cardiovascular systems during yoga practice. OBJECTIVE: The purpose of this study was to delineate the immediate cardiovascular effects of 12 Hatha yoga poses by means of RR (beat-to-beat) intervals and JT (cardiac repolarization) intervals. DESIGN: The research team designed controlled pilot studies based on half-year periods. SETTING: The study took place at the Lithuanian University of Health Sciences in Kaunas, Lithuania. PARTICIPANTS: Participants were women who were long-term yoga practitioners. Three studies occurred: (1) Study 1-10 women with a mean age of 30.1 ± 1.9 years, (2) Study 2-10 women with a mean age of 29.9 ± 1.9 years, and (3) Study 3-22 women with a mean age of 32.9 ± 1.8 years. INTERVENTION: The study examined the acute cardiovascular effects of 12 Hatha yoga poses by means of electrocardiogram parameters. OUTCOME MEASURES: Anthropometrical and physiological parameters were measured: (1) height and weight; (2) body mass index (BMI); (3) heart rate (HR); (4) systolic and diastolic blood pressure (DBP); and (5) electrocardiogram (ECG) RR and JT intervals. RESULTS: The lowest RR interval value was recorded during the Chaturanga Dandasana, at 456.0 ± 16.5 ms in Study 3, with P < .001 compared to the intervals for all the other poses. Significant differences in the JT interval also emerged during the Chaturanga Dandasana, at 177.3 ± 6.0 ms in Study 3 with P < .001 compared to all the other poses. The next lowest RR interval value was recorded in Study 3 during the Utkatasana, at 569.4 ± 17.6 ms. In the Savasana prior to the program, the RR interval increased in study 1 and decreased in studies 2 and 3. The JT interval in the Savasana prior to the program increased in studies 1 and 2 but decreased in study 3. CONCLUSIONS: Healthy women can practice a modified and/or a shorter duration of the Chaturanga Dandasana. Adjustments in the Utkatasana, including having the arms in the prayer position, may help prevent strain to the cardiovascular system. Also, practicing poses with a longer RR interval may aid stress-related health problems.

Interaction between Cardiac Functional Indices during Incremental Exercise Test Reveals the Peculiarities of Adaptation to Exercising.

Background and objectives: Physical load causes structural changes in the heart that vary depending on the type of training and may affect the function of the heart. Aim of the study: To determine, using the applied co-integration method on algebraic data, the impact of sprinting and of endurance adaptation on the dynamic interactions of cardiovascular functional indices while participants were performing under an increasing workload, up to their inability to continue. Materials and Methods: Healthy athletes were chosen to take part in this study and were separated into two groups: Sprinters (n = 11) and endurance athletes (n = 13). The bicycle ergometric method of incremental increase in a provocative workload (graded stress) was used. The heart rate, stroke volume, and cardiac output were determined using the tetrapolar rheography method. Results: Individuals who are adapted to endurance while carrying physical loads, in contrast to well adapted sprinters, are characterized with a lower rate of changing the pace of interactions between stroke volume and cardiac output while performing at an increasing workload up to their inability to continue. Also, endurance athletes displayed a long and relatively stable phase as well as a greater decrease of interaction between indices at the end of the workload. At the beginning of the exercise, the interaction between the stroke volume and the cardiac output was reduced. However, as the physical load continued, this interaction became significantly stronger. The comparison of the stroke volume and the cardiac output's dynamic interaction revealed that the endurance group had a greater working capacity. Conclusions: Typical dynamics of interactions during the testing with an increasing physical load can be differentiated into separate phases: The decrease of interaction at the onset of the load, the increase during the continuation of an increased workload, and the decrease at the last stages of the load.

The characterization of the transit through the anaerobic threshold based on relationships between RR and QRS cardiac intervals.

This paper aims to develop a novel computational technique for the detection of the transit through the anaerobic threshold. This technique uses only cardiac intervals derived from the electrocardiogram and is based on algebraic relationships between RR and QRS intervals. Electrocardiograms are measured during the load and the recovery processes. Algebraic relationships between cardiac intervals are used not only to identify the anaerobic threshold but also to characterise individual features of the person during the transit through the threshold. The ratio between carbon dioxide and oxygen in the exhaled air is used to validate the results. The algebraic relationship between cardiac intervals serves as a stand-alone indicator for both the determination of the anaerobic threshold and the characterization of the performance of the person during the load and the recovery processes.

Correlation between Changes in Local Earth's Magnetic Field and Cases of Acute Myocardial Infarction.

The impact of changes in the geomagnetic field on the human body remains the subject of studies across the world, yet there is no consensus. Current studies are observing effects that require further work by researchers in order to find out the mechanisms that would allow a proper assessment of the correlations between the Earth's magnetic field variations and changes in human organisms. The main purpose of this study was to investigate possible correlations between the strength of time-varying aspects of the local Earth's magnetic field and incidence of myocardial infarctions. Study participants included 435 males and 268 females who had diagnosis of myocardial infarction during the period of 1 January 2016 to 31 December 2016 and attended the Department of Cardiology at the Hospital of Lithuanian University of Health Sciences (LUHS), Kauno klinikos. Time varying magnetic field data was collected at the magnetometer site located in Lithuania. After mathematical analysis, the results support the hypothesis that the Earth's magnetic field has a relationship between the number of acute myocardial infarction with ST segment elevation (STEMI) cases per week and the average weekly geomagnetic field strength in different frequency ranges. Correlations varied in different age groups as well as in males and females, which may indicate diverse organism sensitivity to the Earth's magnetic field.

Long-Term Study of Heart Rate Variability Responses to Changes in the Solar and Geomagnetic Environment.

This long-term study examined relationships between solar and magnetic factors and the time course and lags of autonomic nervous system (ANS) responses to changes in solar and geomagnetic activity. Heart rate variability (HRV) was recorded for 72 consecutive hours each week over a five-month period in 16 participants in order to examine ANS responses during normal background environmental periods. HRV measures were correlated with solar and geomagnetic variables using multivariate linear regression analysis with Bonferroni corrections for multiple comparisons after removing circadian influences from both datasets. Overall, the study confirms that daily ANS activity responds to changes in geomagnetic and solar activity during periods of normal undisturbed activity and it is initiated at different times after the changes in the various environmental factors and persist over varying time periods. Increase in solar wind intensity was correlated with increases in heart rate, which we interpret as a biological stress response. Increase in cosmic rays, solar radio flux, and Schumann resonance power was all associated with increased HRV and parasympathetic activity. The findings support the hypothesis that energetic environmental phenomena affect psychophysical processes that can affect people in different ways depending on their sensitivity, health status and capacity for self-regulation.

Identification of a Group's Physiological Synchronization with Earth's Magnetic Field.

A new analysis technique for the evaluation of the degree of synchronization between the physiological state of a group of people and changes in the Earth's magnetic field based on their cardiac inter-beat intervals was developed and validated. The new analysis method was then used to identify clusters of similar synchronization patterns in a group of 20 individuals over a two-week period. The algorithm for the identification of slow wave dynamics for every person was constructed in order to determine meaningful interrelationships between the participants and the local magnetic field data. The results support the hypothesis that the slow wave rhythms in heart rate variability can synchronize with changes in local magnetic field data, and that the degree of synchronization is affected by the quality of interpersonal relationships.

Synchronization of Human Autonomic Nervous System Rhythms with Geomagnetic Activity in Human Subjects.

A coupling between geomagnetic activity and the human nervous system's function was identified by virtue of continuous monitoring of heart rate variability (HRV) and the time-varying geomagnetic field over a 31-day period in a group of 10 individuals who went about their normal day-to-day lives. A time series correlation analysis identified a response of the group's autonomic nervous systems to various dynamic changes in the solar, cosmic ray, and ambient magnetic field. Correlation coefficients and p values were calculated between the HRV variables and environmental measures during three distinct time periods of environmental activity. There were significant correlations between the group's HRV and solar wind speed, Kp, Ap, solar radio flux, cosmic ray counts, Schumann resonance power, and the total variations in the magnetic field. In addition, the time series data were time synchronized and normalized, after which all circadian rhythms were removed. It was found that the participants' HRV rhythms synchronized across the 31-day period at a period of approximately 2.5 days, even though all participants were in separate locations. Overall, this suggests that daily autonomic nervous system activity not only responds to changes in solar and geomagnetic activity, but is synchronized with the time-varying magnetic fields associated with geomagnetic field-line resonances and Schumann resonances.

New approach for visualization of relationships between RR and JT intervals.

This paper presents the concept of perfect matrices of Lagrange differences which are used to analyze relationships between RR and JT intervals during the bicycle ergometry exercise. The concept of the perfect matrix of Lagrange differences, its parameters, the construction of the load function and the corresponding optimization problem, the introduction of internal and external smoothing, embedding of the scalar parameter time series into the phase plane-all these computational techniques allow visualization of complex dynamical processes taking place in the cardiovascular system during the load and the recovery processes. Detailed analysis is performed with one person's RR and JT records only-but the presented techniques open new possibilities for novel interpretation of the dynamics of the cardiovascular system.

The effect of differential training-based occupational therapy on hand and arm function in patients after stroke: Results of the pilot study.

OBJECTIVE: The aim of this study was to evaluate the effect of differential training-based occupational therapy on the recovery of arm function and to compare these data with the results obtained after conventional occupational therapy. METHODS: A total of 27 patients who had suffered a cerebral infarction in the left brain hemisphere were recruited for the study. There were 9 men (33.33%) and 18 women (66.67%). All the patients had paresis of the right arm. The patients were divided into 2 groups: the control group comprised 15 patients who were given conventional occupational therapy (5 times per week) and the study group consisted of 12 patients who underwent conventional occupational therapy (3 times per week) along with occupational therapy based on differential training (2 times per week). RESULTS: In the control group, the mean performance time of only 2 tasks, i.e., flip cards and fold towel, improved significantly (P<0.05), while significant deterioration in the mean performance time of the task "lift can" was observed (P<0.05). In the study group, the mean performance time of all the tasks except for forearm to box (side), hand to box (front), and lift paperclip improved significantly (P<0.05), and no deterioration in arm function was observed. CONCLUSION: Both patients' groups improved arm function after occupational therapy sessions, but the patients who underwent conventional occupational therapy along with differential training-based occupational therapy recovered their arm function more effectively than their counterparts after conventional occupational therapy.

Constraints-controlled metastable dynamics of exercise-induced psychobiological adaptation.

A fundamental question in the theory of psychobiological adaptation and specifically of sports training is the problem of how adaptation to sports performance demands occurs as a consequence of systematic exercise. In this position paper, we review some results of our previous and current research conducted on several different levels of exercise-induced effects. Based on these results, we contend that the control of psychobiological systems during exercise is constraints based. Constraints direct the flow of behavioral changes on a rugged metastable landscape. Such adaptive behavior is soft-assembled, consisting of context-sensitive cooperative configurations of system components that dwell on different time scales.

Assessment of functional conditions of basketball and football players during the load by applying the model of integrated evaluation.

UNLABELLED: We consider the human body as an adaptable, complex, and dynamic system capable of organizing itself, though there is none, the only one, factor inside the system capable of doing this job. Making use of the computerized ECG analysis system "Kaunas-load" with parallel registration of ECG carrying out body motor characteristics, ABP, or other processes characterizing hemodynamics enable one to reveal and evaluate the synergistic aspects of essential systems of the human body what particularly extends the possibilities of functional diagnostics. The aim of the study was to determine the features of alterations in the functional condition of basketball and football players and nonathletes during the bicycle ergometry test by applying the model of evaluation of the functional condition of the human body. MATERIAL AND METHODS: The study population consisted of 266 healthy athletes and nonathletes. Groups of male basketball players, male football players, male nonathletes, female basketball players, and female nonathletes were studied. A computerized ECG analysis system "Kaunas-load" that is capable of both registering and analyzing the power developed by the subject and 12-lead ECG synchronically were used for evaluating the functional condition of the CVS. The subject did a computer-based bicycle ergometry test. The following ECG parameters at rest and throughout the load - HR, JT interval, and the deduced JT/RR ratio index that reflects the condition between regulatory and supplying systems - were evaluated. After measuring ABP, the pulse amplitude (S-D) was evaluated. The pulse blood pressure ratio amplitude (S-D)/S that depicts the connection between the periphery and regulatory systems was also evaluated. Speeds of changes in physiological parameters during physical load were evaluated too. RESULTS: Heart rate and JT/RR ratio of athletes at the rest and during load were lower, and JT interval of rest was longer and became shorter more slowly during load, compared to that of healthy nonathletes. The pulse arterial blood pressure amplitude of men at rest and during load was higher than that of women. The pulse ABP amplitude of athletes was higher than that of nonathletes. The relative pulse ABP amplitude in the state of rest in the groups of men was higher than in groups of women. The relative pulse amplitude of female basketball players at rest and during load was higher than that of female nonathletes. Significant differences in the dynamics of speed of changes in HR, the pulse ABP amplitude, and the relative pulse ABP amplitude of male and female basketball players, male football players, as well as male and female nonathletes were observed. CONCLUSIONS: The newly deduced parameters, namely, speeds of changes in the parameters with changes in the phase of the load reflect very well peculiarities of functional condition of the human body during bicycle ergometry test. The sum total of those newly deduced parameters and customary parameters reveals new functional peculiarities of the human body.

Functional state assessment on the dynamics of interparametric concatenations during exercise tests.

The aim of this study was to complement an analytical approach by new methodology of data sequences analysis of muscular and cardiovascular indices during the assessments of functional state. The participants of the study were 14 elite Greco-roman wrestlers and they underwent two exercise tests 30 squats per 45 s while 12-lead ECG was recorded continuously and 30-s vertical jumps test while the height, contact and flight times of each jump recorded. The parametric interactions parameters and their sequences analysis based on a mathematical method founded upon a matrix theory were applied. The obtained results enabled to identify dynamical changes of the independence of parameters or an opposite phenomenon - interaction. The dynamics of ECG or performance parameters did not allowed to find out the moments of critical changes during the exercising. The dynamics of concatenation between the time of push-off and the height of jumps while performing repeated jumps has a tendency to increase in the values of discriminant and the fluctuations at some point of jumping task comes on. Analysis of concatenation between ECG or muscle performance parameters allows distinguishing the individual peculiarities which could be in value of discriminant, in time of exercising before the fluctuations occurs, in character how the body behave as to compensate fatigue. It was concluded that assessment the dynamics of inter-parametric concatenation of physiological parameters based on the data sequences analysis provide a new approach in the field of functional state assessment allowing to reveal features of functional preparedness and fatigability during workloads.

Implementation of international transtelephonic ECG platform for patients with ischemic heart disease.

Ischemic heart disease in European countries over decades causes up to 55% of all cases of sudden death and also has a high rate of mortality, morbidity, and hospital admission. Patients with such chronic diseases also require intensive home care facilities from community nurses. The aim was to establish international multilingual platform for transtelephonic ECG system as an alternative solution for home care and assess its performance. METHODS. During this pilot study, the international toll-free line between Lithuania and Germany was established, and practical applicability of the tele-ECG device was tested. Transtelephonic ECG system was implemented between Telemedicine Center in Bad Segeberg (Bad Segeberg Clinic, Germany), the Call Center in Kaunas at the Hospital of Kaunas University of Medicine, and a patient residence. RESULTS. Over a 6-month follow-up period, 34 patients were recruited. Following the ECG transmission, 86 teleconsultations were done. During the study, a total of 329 ECGs were sent by the patients; out of them, 14 ECGs were with clinical changes. Technical problems due to insufficient patient training, telecommunication systems, acoustic data transmission, and device itself were reported. Up to 23% of ECGs sent by patients were unreadable and not applicable for further clinical analysis. CONCLUSIONS. Our study showed the potential of telemedicine facilities to overcome the problems of access that makes the technique so potentially useful, but for telemonitoring application at patient homes in a wider population, it needs to be improved in terms of technical performance, transmission and analysis automatization.

Nonlinear dynamics analysis of electrocardiograms for detection of coronary artery disease.

A computerized approach of nonlinear dynamics analysis of electrocardiogram (ECG) signals was applied for the detection of coronary artery disease (CAD). The proposed nonlinear dynamics descriptors were derived from 12-lead rest ECG data, and evaluated by originally developed computer software. Fluctuations of potentials of ECG leads that occur during the period of 20 ms with a magnitude of 5-20 microV were significantly less beat-to-beat predictable in ischemic versus non-ischemic patients. The well-known nonlinear dynamics descriptors, recurrences percentage, mutual information, fractal dimension, and a new descriptor, next embedding dimension error, were good quantitative descriptors of fluctuations. They were significantly different (< p = 0.00001) in males with (108 patients) and without (54 patients) coronary artery lesions. The analysis of small fluctuations required a careful preprocessing technique based on knowledge of specifics of measurement errors and physiology of ECG signals. We considered finite differences of measured potentials with the time step of 20 ms as the initial source for nonlinear analysis. In nonlinear dynamics analysis, we also included such time moments that only belong to P- and T-waves or baseline drift with small positive slopes that allowed us to extract, under normal conditions, initial halves of P- and T-waves that displayed a better capacity to classify ischemic patients.

[Characteristics of changes in oxygen saturation in muscular tissue and ischemic episodes in cardiac muscle during the bicycle ergometry]. / Deguonies isotinimo raumenyse ir funkciniu iseminiu reiskiniu miokarde kitimo ypatybes atliekant pakopomis didejanti kruvi veloergometru.

There is a strong need for more studies devoted to the analysis of changes in physiological processes during the incremental bicycle exercise when increasing the intensity of physical activity, serious ischemic episodes in cardiac muscle occur. The aim of this study was a synchronous observation of physiological changes during bicycle ergometry. Participants of the study were 27 healthy male volunteers. All participants of the study performed a graded exercise test to maximal efforts. A 12-lead electrocardiogram was recorded during exercise test and the first three minutes of recovery. Heart rate and ST-segment depression (sum of negative amplitudes) was analyzed. InSpectra Standad System Model 325 (Hutchinson Technology, Hutchinson, Minnesota, USA) was used for the registration of changes in oxygen saturation during exercise and recovery. The InSpectra sensor was placed on m. vastus lateralis. The results obtained in this study showed that changes in oxygen saturation depended on the intensity of workload. During the incremental increase in workload, oxygen saturation decreased in active muscles. While performing the final stages of exercise, a gradual increase in oxygen saturation is observed in the muscles of some participants. Increasing the intensity of physical activity to maximal efforts, rise in oxygen saturation (second phase) coincides with augmentative ischemic episodes in cardiac muscle.