We present a case of a new ECG phenomenon that has not been described previously in patients with long QT syndrome (LQTS). Prolongation of the QT interval (QTc) to 568 ms were revealed in girl 6 years old on the resting ECG. There were no symptoms, syncope or family history of sudden death. A molecular genetic study revealed mutation «de novo» in the SCN5A gene (p.Val1411Met), a pathogenic class V that typical for the third molecular genetic variant of LQTS (LQT3). During Holter monitoring a «hyperadaptation» of the QT interval was noted (slope QT/RR 0.37 with normal limit till 0,24). New ECG pattern of the combination T wave alternans and QRS alternans (AT/AQRS) at the night sleep (possibly in REM sleep) were recorded. This pattern has not been described previously in patients with LQTS. Atenolol 1 mg/kg was prescribed. During therapy, AT/AQRS did not record after 2 months. Possible mechanisms and prognostic significance of the identified ECG pattern, issues of treatment of patients with LQT3 are discussed. Conclusions: Combined of T wave alternans and QRS alternans (AT/AQRS) is a new ECG pattern in patients with LQTS that is likely to increase the risk of cardiac events. “Hyperadaptation” of the QT interval may be one of the electrocardiological features of LQT3. The emergence of the AT/AQRS pattern during REM sleep makes this period perhaps the most dangerous for the development of cardiac events in patients with LQT3.

Specialized devices for fixing thoracic electrodes in newborns and children weighing up to 4000 g have been developed. The devices are offered in 3 versions: for children weighing up to 2000 g, from 2000 g to 3000 g and from 3000 g to 4000 g. The devices allow high-quality, stable and safe fixation of thoracic electrodes on the chest of a child, including low body weight.

The syncope in children with bradyarrhythmias can be life-threatening and their differentiation is important in the evaluation of any child with syncope. In children risk factors for the poor prognosis and progression of bradyarrhythmias leading to the development of arrhythmogenic syncope have not been definitively determined. The aim was to determine the diagnostic significance of the implantable cardiac monitors (ICM) method and identify electrocardiographic and electrophysiological predictors of the development of syncope in children with bradyarrhythmias. Material and methods. The authors analyze the group of 191 children with bradyarrhythmias, recurrent syncope and ICM. The examination of patients included electrocardiography (ECG), echocardiography (ECHO-CG), Holter monitoring (HM) of rhythm, electrophysiological study (EHS), exercise test, and analysis of family anamnesis data. Results. 96 out of 191 children had positive result of long-term cardiac monitoring. 16 out of 96 children had structural heart deseases – congenital heart defects, cardiomyopathies. Episodes of arrhythmias were documented in 30% of children during syncope and asymptomatic arrhythmias were observed in 43% of children. Arrhythmogenic syncope accounts for 7,5% of all registered syncope and 5% of positive monitoring results. Sinus rhythm during syncope was registered in 48% of children, and 2% of patients had a combination of arrhythmogenic and non-arrhythmogenic syncope. The heart rhythm characteristics of standard ECG and HM in patients with symptomatic arrhythmias did not differ significantly from either patients with asymptomatic episodes of arrhythmias or patients with sinus rhythm during syncope. Conclusion. The diagnostic significance of the ICM for identifying the cause of recurrent syncope in children with bradyarrhythmias is 50%. Arrhythmogenic genesis of syncope has been confirmed in 7.5% of children with bradyarrhythmias. The heart rate characteristics and electrophysiological parameters of the previous examination are not predictors of the development of syncope in children with bradyarrhythmias. Long-term cardiac monitoring of ICM can identify children with life-threatening arrhythmogenic syncope from all patients with bradyarrhythmia and make the prevention of sudden cardiac death (SCD).

The review covers current clinical guidelines for the use of electrocardiography (ECG) in examining patients with pulmonary hypertension (PH), provides data on the correlation of ECG parameters with hemodynamic parameters in PH, discusses the possibilities of using ECG in PH screening, including the inclusion of ECG parameters in clinical scales. Particular attention is paid to data on the relationship between ECG changes and the prognosis of patients with PH and the use of ECG to assess the effectiveness of PH treatment, in particular, pulmonary artery balloon angioplasty in chronic thromboembolic pulmonary hypertension. Special sections are devoted to such ways of improving electrocardiographic diagnostics of PH as the use of three-dimensional vectorcardiographic parameters and ECG processing using deep machine learning methods. The paper describes «soft» functional tests that can potentially provide useful information in the diagnosis of PH (fluid challenge, passive leg raise, deep inhalation).

Purpose: to evaluate the clinical significance of left ventricular myocardial deformation indicators, their relationship with the degree of heart failure and left ventricular hypertrophy in children with hypertrophic cardiomyopathy (HCM). Materials and methods. 61 patients with primary genetically confirmed asymmetric HCM aged 7 to 17 years underwent a comprehensive clinical and echocardiography. Echocardiography determined indicators of left ventricular systolic function: ejection and shortening fractions, global longitudinal, circular and radial myocardial deformations and deformations rates. The assessment of myocardial hypertrophy of left ventricular segments was performed taking into account absolute values in systole and diastole depending on age, recalculated per standard deviation units in the population (Z-score factor). Results. A more pronounced degree of heart failure, a decrease in ejection and shortening fractions, and indicators of left ventricular myocardial deformation were established in all children with non-obstructive and obstructive forms of HCM and an extreme degree of myocardial hypertrophy, in contrast to the non-obstructive form of the disease with a less pronounced degree of hypertrophy. An earlier decrease in myocardial deformation indices was revealed in comparison with ejection and shortening fractions, longitudinal deformation and its speed in comparison with radial and circular, their speeds. Conclusions. 1. In children with HCM and extreme degrees of left ventricular myocardial hypertrophy, compared with mild and moderate hypertrophy, a more pronounced degree of heart failure is observed, which is accompanied by a decrease in left ventricular systolic function. Among them, a decrease in myocardial deformation rates and their velocities is more sensitive compared to left ventricular ejection fractions and shortening. 2. Reduction of left ventricular myocardial deformation in children with HCM depends on the degree of hypertrophy. The earliest, manifesting itself even with a mild degree of hypertrophy, is a decrease in longitudinal deformation and its speed compared to circular and radial deformations and their speeds. 3. Determining the indicators of left ventricular myocardial deformation in children with HCM in comparison with the degree of myocardial hypertrophy is of great clinical importance in assessing the systolic function of the left ventricle to optimize administration tactics and timely treatment of the disease.

The article highlights the possibility of application of exercise tests without special equipment. The methodological features of conducting tests and their interpreting options are shown. Changed body position tests have been updated. The definitions of stress tests and exercise tests have been clarified. A classification of ergometers and indicators of monitored parameters has been worked out. Examples of medical reports are given. The application possibilities of stress tests were considered in real clinical practice at the stages of treatment and rehabilitation of patients with a wide range of nosologies. Tables for independently determining the exercise test results are presented. The methods can be used in pediatric practice. The article is addressed to a wide range of practitioners and functional diagnostics specialists.

Introduction. Yoga breathing exercises that involve voluntary changes in pulmonary ventilation parameters can potentially influence cerebral circulation due to changes in CO2 content in arterial blood. Objective. To assess the effect of yoga breathing exercises with changes in pulmonary ventilation levels on blood flow parameters in the middle cerebral artery (MCA). Methods. The study included 21 participants, with an average age of 39.5±8.7 years, who were capable of performing yoga exercises at respiratory rates (RR) of 3–3.5/min and 1–1.5/min. For 5 minutes, participants underwent three stages: free breathing (stage 1), breathing with RR=3–3.5/min (stage 2), and breathing with RR=1–1.5/min (stage 3). During stages 2 and 3, the «full breathing» technique, which involves maximum deep inhalation and exhalation, was employed. Respiratory rate (RR), tidal volume (TI), minute ventilation (MV), end-tidal CO2 partial pressure (PetCO2), and oxygen fraction in exhaled air (FeO2) were recorded using spiro-gas analysis. Transcranial duplex scanning was used to measure peak systolic blood flow velocity (Vps), end-diastolic blood flow velocity (Vd), time-averaged maximum blood flow velocity (TAMAX), and resistance index (RI) in the right MCA. The velocity variation index (VVI) was calculated for each stage. Results. Compared to stage 1 (free breathing), stage 2 (RR = 3–3.5/min) showed an increase in MV and FeO2, a decrease in PetCO2, and reductions in Vps, Vd, and TAMAX, with an increase in RI. VVI decreased statistically insignificantly. In stage 3 (RR = 1–1.5/min), compared to stage 1, there was an increase in PetCO2, a decrease in MV and FeO2, and increases in Vps, Vd, and TAMAX, with a decrease in RI. VVI increased significantly. Conclusions. Yoga breathing exercises at respiratory rates of 3–3.5/min and 1–1.5/min result in multidirectional shifts in ventilation and gas exchange parameters, leading to changes in arterial cerebral blood flow (a decrease and increase in blood flow velocity with an increase and decrease in MV, respectively). VVI, reflecting fluctuations in blood flow velocity, increases significantly with reduced MV, likely due to the vasodilatory effect of CO2.