The traditional EEG spectral analysis is not suitable for the study of dynamic processes in the brain, since the size of the recording segments required for plotting the spectrum graphs should be significantly longer than the physiological variability of the electroencephalogram itself. For these purposes, special methodological approaches have been developed: dynamic observation of EEG rhythms using the Berg-Fourier analysis method and various options for plotting trends of frequency and amplitude values of brain potentials. Almost no one knows the real significance of fluctuations in the frequency of the dominant EEG rhythm, since in fact there was no instrument for studying this phenomenon in dynamics. In panic attacks with a high level of anxiety, the opposite picture is observed, a pathological decrease in the severity of fluctuations in the frequency of the alpha rhythm.
The relevance of this development is due to the fact that prolongation or shortening of the QT interval is associated with an increased risk of sudden cardiac death and there is no validated and recognized method to calculate corrected QT interval (QTc) in left bundle branch block (LBBB).
The aim of the study is to develop a method for evaluating the duration of corrected QT interval in patients with LBBB. Electrocardiogams (ECGs) of 43 patients, including 31 women and 12 men, were analyzed. Patients were included in the study if they had ECGs before and after the manifestation of LBBB. At the same time the heart rate (HR) on ECGs should have been 50–90 bpm and the difference in heart rate on ECGs with and without LBBB was no more than 10 bpm. Patients who have suffered myocardial infarction were excluded from the study. Based on the analysis of ECGs before and after the manifestation of LBBB, two methods to calculate QTc have been developed. These methods make it possible to compensate for prolongation of the QT interval caused by enlargement of QRS and demonstrated high accuracy in the calculation of QTc by different formulas, comparing the calculated values for LBBB and values of QTc before the development of LBBB.
1. Linear regression method
Bazett QTclinB = 120,5692 + 0,6315 x QTcBb
Fridericia QTclinF = 130,4425 + 0,6024 x QTcFb
Sagie QTclinS = 125,4726 + 0,6182 x QTcSb
QTcBb. QTcFb. QTcSb – the duration of the corrected values of QT in LBBB according to the formulas of Bazett, Fridericia, Sage, respectively.
2. Method of QT interval compensation for enlargement of QRS in LBBB
QTк = QTb – (QRSb – 100 ms) and the subsequent calculation of QTc by the formulas of Bazett, Fridericia, Sage based on the values of QTк.
A thesaurus (logically ordered list) of statements for the ECG annotation has been developed. 549 ECGs from the PTB Diagnostic ECG Database were independently annotated by 3 clinicians using this thesaurus and web interface. The resulting independent annotations did not match (the proportion of matches was from 3 to 100% for different groups of conclusions in pairwise comparison of annotators). The annotations were agreed, for which a special procedure was developed. The procedure includes participation of moderators (highly qualified physicians) and using videoconferencing. Annotations are published in the public domain and can be used both for the purposes of knowledge control and for testing the accuracy of the automatic ECG analysis algorithms and software.
Purpose: to search for the parameters of the daily variability of the sinus rhythm (VSR) and VSR corresponding to different ranges of heart rate changes, which are most strongly affected by pulmonary hypertension of various etiologies and severity.
Material and methods. The study included 67 patients (18 men and 49 women aged 18 to 59 years) with two types of pulmonary hypertension: 42 patients (6 men and 36 women) with idiopathic pulmonary hypertension (IPH) and 25 patients (12 men and 13 women) with chronic thromboembolic pulmonary hypertension (CTPH). Some patients examined two or more times at different hospitalizations. As a result, 224 examinations conducted in combination with Holter ECG monitoring and subsequent analysis of the daily VSR. As a control group, the results of XM ECG of 67 healthy individuals (29 women and 38 men aged 18 to 55 years) were used. The daily HRV evaluated in age-comparable subgroups of control groups and PH: 18–29 years, 30–39 years, 40–49 years and 50–59 years. HRV parameters were determined using a modification of the VSRA-SSR method, taking into account the presence of double fractures (DFR) on the rhythmogram.
Results. 1) The appearance of IPH, CTPH and the increase in PH FC have approximately the same effect on the parameters characterizing the daily HRV as a whole, and on the HRV parameters corresponding to different ranges of heart rate changes. 2) The effect of PH on HRV clearly depends on the age of the patient and the severity of the disease characterized by PH FC. At the age of 40, both the appearance of PH and the increase in PH FC generates a tendency to decrease HRV, regardless of the presence or absence of DIR. At the age of over 40 years, this trend begins to weaken, and at the age of 50–59 years, in areas with DIR, it changes to a tendency to increase HRV with increasing severity of the disease. 3) The most obvious effect of PH on HRV is manifested in the form of a decrease in HRV in the areas of the rhythmogram without DIR. This applies both during the whole day and in all ranges of heart rate changes studied by us. 4) The effect of PH on HRV is most expressed in the heart rate ranges > 75 beats/min. 5) The data obtained can be useful to analyze the relationship between the dynamics of the daily HRV with the dynamics of the parameters of the functional state of the patient with PH, obtained according to his clinical and instrumental examination.
Our aim was to determine parameters of motor evoked potential (MEP) from the tongue in healthy children of different age.
Methods. 40 healthy children (age range from 2 years old to 17 years, 14 females & 26 males) were enrolled. All underwent diagnostic TMS, single-pulse protocol, 150-sm round coil, Neiro-MS-D device. Coil was placed on Fz point, registration was performed by the surface electrode on the middle line of the tongue.
Results. MEPs were registered in all cases, its average latency was 6,29±0,64 ms, average amplitude – 0,76±0,24 µV. There were neither gender differences nor amplitude. Significant age difference (p<0.001) was registered between young children (age 2–5 years) and two older groups on latency.
Conclusion. There is a significant age difference in MEPs’ latency between young children and older group. This may be associated with age elongation of the conductors due to the growth of the nervous system. The obtained normative data can be used as a tool for an objective assessment in children with various pathological speech disorders.
Presented clinical case demonstrates a successful surgical treatment results of long-term existing hemodynamically significant congenital heart disease (secondary atrial septal defect and pulmonary stenosis with secondary tricuspid regurgitation) in a patient with HIV infection after correction the immunodeficiency status and reducing the viral load.
The article highlights the experience of ultrasound and functional diagnostics imaging doctor’s work in the «red zone» at the time of new COVID‑19 coronavirus infection pandemic. Echocardiography is a valuable tool in the assessment of right ventricular disfunction and pulmonary hypertension degree, acute virus myocarditis and acute coronary syndrome. Transthoracic and transesophageal echocardiography is used to monitor the patient’s condition during treatment with extracorporeal membrane oxygenation (ECMO) and multiple organ failure syndrome.
The article analyzes the current state of thermal imaging research in the field of screening and assessment of the severity of the condition in a widespread upper limb disease associated with repetitive strain injury (RSI). Temperature distributions on the surface of the skin of the hands, due to professional activities and working conditions, are considered in detail in terms of their applicability and effectiveness in mass occupational medical examinations, as well as in ergonomic developments.
The author of this article entered into a discussion with the authors of these articles ‘Questionnaire …’ and ‘Rules …’, believing that the issues they discussed were at least half a century behind modern possibilities. The author believes that, without detracting from the success of EEG in the field of diagnosing epilepsy, the development of electroencephalography in the study of mental functions, where quantitative EEG should play a significant role, is an urgent problem. In the author’s opinion, the brake on the development of this direction is the poor knowledge of these issues not only by practical neurophysiologists, but also by teaching staff at advanced training departments. One of the main reasons for this is the inadequate level of mathematical support in the software products of the leading companies producing computer electroencephalographs.
ISSN 2949-2807 (Online)
