Comparative evaluation of autonomic regulation of circulation in patients undergone coronary artery bypass grafting or correction of acquired valvular heart disease

The aim of the research was to study the peculiarities of vegetative regulation of blood circulation in cardiac surgery patients who underwent coronary artery bypass grafting (CABG) or correction of acquired valvular heart disease (CAVHD). Material and Methods. In this study we included 42 patients (12 women; 63 (57; 67) years), who underwent CABG, and 36 patients (16 women; 58 (47; 65) years) who underwent CAVHD. The synchronous 15 minutes records of electrocardiogram and photoplethysmogram (PPG) were performed in all patients before and after surgery. Time domain and frequency domain measures of heart rate variability (HRV) and index of synchronization between low-frequency (LF) oscillations in HRV and PPG (index S) were analyzed. Results. Most studied autonomic indices did not have statistically significant differences between patients with CABG and CAVHD in the study stages, except for heart rate, which was higher in patients before CAVHD (p=0,013). Conclusion. The values of HRV and index S do not depend on the difference in the clinical status and the features of performed cardiac surgical interventions between patients with CABG and CAVHD.</p

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

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

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

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

Synchronization of low-frequency rhythms in electroencephalogram by respiration with linear dependent time frequency.

The aim of the present study was to investigate the features of interaction of low-frequency rhythms in delta band of electroencephalogram (EEG) and processes in vegetative regulation of circulation with respiration. Materials and methods. 19 leads of EEG, photoplethysmogram (PPG) and respiration were simultaneously recorded in four healthy males (19-25 years old) during 30 minutes physiological test with linearly increasing frequency of respiration. Modern methods of nonlinear dynamics were used to diagnose the presence of phase and frequency synchronization between respiration and low-frequency rhythms in delta band of EEG and in PPG. Results. We found significantly long sections of synchronization of delta rhythms in cervical leads of EEG and low-frequency rhythms in PPG by respiration with linearly increasing frequency. Conclusion. Obtained results correlate well with established hypothesis which suggest that low-frequency rhythms in baroreflectory regulation of circulation are in complex dynamic relationships with structures of brain stem. A method was proposed for quantitative evaluation of synchronization strength between respiration and low-frequency rhythms in electrical brain activity in physiological tests with respiration with frequency linearly increasing in time

Организация рабочих процессов по рекрутингу доноров и заготовке реконвалесцентной плазмы в период пандемии COVID-19

Background. The pandemic of the new coronavirus infection has challenged the medical community for quickly finding and implementing effective methods of treatment. In the absence of a vaccine or specific therapy with proven effectiveness, the usage of convalescent plasma can be the one of perspective methods. An important aspect of this technology is the efficient and safe preparation of convalescent plasma. To date, in the world literature there are practically no publications about donor recruitment and the specifics of the preparation of convalescent plasma. Purpose of the research. Presentation of the experience of organizing a workflow for recruiting donors and stockpiling of convalescent plasma with a high titer of virus-neutralizing antibodies to SARS-CoV-2. Methods. The analysis of the work of the Blood Service of the Moscow Department of Health for stockpiling of COVID-19 convalescent plasma has been executed. In total it has been stockpiled 1240 doses. The normative documentation has been developed by a working group on the basis of the current federal legislation of Russian federation and been approved by the Moscow Department of Health. The titer of neutralizing antibodies (VNA) has been determined as the basic method for assessing the immunological viability of convalescent plasma. The main characteristics of donors, the characteristics of the disease course, the results of preliminary testing for the presence of specific antibodies by ELISA and CLIA methods has been compared with VNA titers in the stockpiled convalescent plasma. Results. Due to a Moscow Health Departments order No. 325 dated 01.04.2020 (a basic local regulatory document) it has been developed a regulation for the stockpiling, examination, storage, safety and transfering of fresh frozen pathogen-reduced plasma of COVID-19 convalescent donors to medical organizations of the Moscow Health Department. For arranging an interaction with donors it has been created a call-center. For effective preliminary selection, it has been formed a donor characteristics list, which has been combined with screening of specific antibodies by ELISA and CLIA methods. Conclusions. Developed a system of recruiting donors and procurement process of convalescent plasma for treatment СOVID-19, which includes the necessary regulations, algorithms for the selection and recruitment of donors, the registry of donors and recipients, algorithms, efficiency and safety of convalescent plasma.Обоснование. Пандемия новой коронавирусной инфекции поставила перед медицинским сообществом задачу быстрого поиска и внедрения эффективных методик лечения. В условиях отсутствия вакцины и средств специфической терапии с доказанной эффективностью в качестве одной из перспективных методик рассматривается трансфузия реконвалесцентной плазмы (РП). Важным аспектом данной технологии является заготовка эффективного и безопасного компонента. На сегодняшний день публикации по рекрутингу доноров и особенностях заготовки РП в мировой литературе практически отсутствуют. Цель исследования Анализ опыта организации рабочего процесса по привлечению доноров и заготовке РП с высоким титром вируснейтрализующих антител к SARS-CoV-2. Методы. Проведен анализ работы Службы крови Департамента здравоохранения г. Москвы (ДЗМ) по заготовке РП COVID-19. Всего заготовлено 1240 доз. Нормативная документация разработана рабочей группой на основании действующего федерального законодательства и утверждена ДЗМ. Как базовая методика оценки иммунологической состоятельности РП, определен титр вируснейтрализующих антител (ВНА). Проведено сопоставление основных характеристик доноров, особенностей течения заболевания, результатов предварительного тестирования на наличие специфических антител методами ИФА и ИХЛА с титрами ВНА заготовленной РП. Результаты. Работа по заготовке, обследованию, хранению, обеспечению безопасности и передаче в медицинские организации ДМЗ свежезамороженной патогенредуцированной плазмы доноров-реконвалесцентов COVID-19 была организована на основании приказа ДЗМ от 01.04.2020 № 325 как базового локального нормативного документа. Для оптимальной коммуникации с состоявшимися донорами и привлечения реконвалесцентов использовались ресурсы колл-центра. Для эффективного предварительного отбора доноров применялись анализ характеристик донора (плазма с наибольшими значениями титра ВНА ожидаема от доноров-мужчин, переболевших с признаками явной вирусной пневмонии) и результаты скрининга специфических антител методами ИФА и ИХЛА. Заключение. Разработана система обеспечения рекрутинга доноров и процесса заготовки РП для лечения СOVID-19, включающая необходимые нормативные документы, алгоритмы отбора и привлечения доноров, реестр доноров и реципиентов, алгоритмы обеспечения эффективности и безопасности РП