CONNECTION BETWEEN THE PARAMETERS OF ECG SUPRAVENTRICULAR COMPONENT AND BRONCHIAL HYPERREACTIVITY IN CHILDREN WITH BRONCHIAL ASTHMA

Uncontrolled course of bronchial asthma (BA) is associated with the risk of heart rhythm disturbances. Objective of the study: to analyze the electrocardiographic parameters of the atrial complex and atrioventricular conduction and to assess their relationship with changes in spirometric parameters in tests with dosed physical activity (PA), reflecting bronchial hyperreactivity (BHR) in children with BA. Materials and methods of research: assessment of the parameters of the supraventricular component of the ECG in comparison with changes in spirometric parameters in tests with dosed PA was performed in 55 children aged 6–17 years with atopic asthma. To level the effect of age on ECG indices, the «relative PQ» (rPQ) index was introduced, calculated as the ratio of the patient's PQ interval duration to the median PQ values characteristic of a given age and gender. Results: it was found that a decrease in the Tiffno index (TI) in tests with PA is accompanied by a statistically significant increase in the rPQ index, an increase in the PQ segment (sPQ) and an increase in the proportion of the PQ interval in the structure of the R–R interval (PQ/RR); similar patterns were obtained when comparing the variability instantaneous volumetric expiratory flow rate at the level of 25% of the vital capacity of the lungs (MOS25). Analysis of the available data indicates a statistically significant lengthening of the PQ and sPQ intervals, as well as an increase in the rPQ and PQ/R–R indices in children with BA as the afterload changes in the small bronchi, indirectly assessed by MOC25. Conclusion: children with asthma who have spirometric signs of BHR in the test with PA may have electrocardiographic signs of a slowdown in supraventricular conduction.

Functional methods of investigation of respiratory system in asthma

The article deals with the application of functional methods for the study of the respiratory system, such as spirometry, bronchodilatation test, stress testing to detect bronchial hyperreactivity, provocative test with metacholine, impulse oscillometry, body plethysmography for the diagnosis, following up and prediction of the course of asthma.

Predictive Markers of Bronchial Hyperreactivity in a Large Cohort of Young Adults With Cough Variant Asthma

Cough variant asthma (CVA), a common asthma phenotype characterized by nonproductive cough and bronchial hyperreactivity (BHR), is usually detected by bronchial provocation tests (BPTs) which are time-consuming, expensive, and unsafe. The primary study objective was to provide proof of concept for the use of fractional exhaled nitric oxide (FENO), eosinophil count percentage in induced sputum (sEOS%), forced expiratory flow between 25 and 75% of forced vital capacity (FEF25–75%) % predicted value, and FEF25–75% z-scores as surrogate markers predicting BHR in young adults with suspected CVA; the secondary objective was to compare the diagnostic performance of the various techniques. Three hundred and ten subjects (median age 24 years) were included in a cross-sectional study. Subjects were characterized as BHR positive (POS) (n = 147) or BHR negative (NEG) (n = 163) according to methacholine BPT. Classification accuracies were expressed as areas under the receiver operator characteristic curves (AUC). Compared with BHR NEG, FEF25–75% % predicted value and FEF25–75% z-scores were lower in the BHR POS group (p < 0.001), whereas FENO (p < 0.001) and sEOS% were higher (p < 0.001). AUC values for detecting BHR were as follows: FENO, 0.98 (SD = 0.02); sEOS%, 0.98 (SD = 0.02); FEF25–75% % pred, 0.93 (SD = 0.05); FEF25–75% z scores, 0.92 (SD = 0.05). Optimal cutoff values (OCV) for BHR prediction were as follows: FENO, 32.7 ppb (sensitivity = 0.93, specificity = 0.96), sEOS%, 3.80% (sensitivity = 0.94, specificity = 0.94), FEF25–75% % predicted value, 80.0% (sensitivity = 0.90, specificity = 0.87), and FEF25–75% z-score, −0.87 (sensitivity = 0.89, specificity = 0.87). Non-invasive/semi-invasive airway inflammatory or small airway functional measures might be used as surrogate markers predicting BHR in young adults with suspected CVA.

Is it always easy for children with mild asthma?

Bronchial asthma is the most common chronic disease of children, the worst way is their quality of life. Compliance in the treatment of children is very important, since the actual effect of a drug is determined by both the effective drugs and patient adherence and correct use. A relevant test is the use of mild asthma, which is able to control bronchial hyperreactivity associated with exercise, cold air, and other nonspecific irritants (smoke, odors, etc.). Planning of baseline therapy for children with mild asthma aged 5 years old and younger is particularly problematic for paediatricians due to high incidences of acute respiratory viral diseases and viral-induced exacerbations of bronchial asthma among them. In these children, allergen-specific immunotherapy, long-acting B-agonists, the use of many metered-dose inhaled glucocorticosteroids. are not recommended.Montelukast, an oral antileukotriene drug, has advantages in the treatment of children with mild asthma with virus-induced exacerbations, with asthma of physical exertion and severe bronchial hyperreactivity, especially when combined with allergic rhinitis, as well as in special clinical cases, when parents refuse to use ICS for treatment children with mild asthma or inability to use them for some reason. The use of montelukast for mild asthma in children in the current context of the COVID-19 pandemic also has advantages that pediatricians can use when observing these children in the pediatric area, taking into account contraindications.

Hyperreactivity of the bronchi in children, whooping cough convalescents

Objective: to assess the presence and degree of bronchial hyperreactivity in convalescents of whooping cough based on the results of bronchial provocation tests.Materials and methods. Using bronchial provocative samples with a 0,02/0,33% histamine solution and 0,33% methacholine solution on a PROVOTEST-2 apparatus from PARI, bronchial hyperreactivity was studied in 12 pertussis convalescents aged 7 to 17 years. The level of endogenous nitrogen monoxide in exhaled air (FeNO) was measured using a portable NObreath electrochemical analyzer (from Bedfont Scientific Ltd.).The results. According to the results of BPP, 6 of 12 convalescents of whooping cough were found to have bronchial hyperreactivity of varying degrees. When conducting a breath test with a histamine solution, bronchial hyperreactivity was recorded in three children, in a sample with methacholine, in five. In 3 out of 6 children with revealed signs of bronchial hyperreactivity, the history of atopy was not burdened, which suggests a connection between the pertussis and the development of bronchial hyperreactivity. A significant increase in the level of endogenous nitric monoxide (above 16 ppb) was observed in 2 out of 10 patients. Follow-up observation showed that the duration of cough with whooping cough ranged from 3 to 6 months, and in patients with positive results of several tests it was maximum. Two out of three children with bronchial asthma showed elevated levels of FeNO and samples with methacholine. Follow-up observation showed that whooping cough aggravated bronchial asthma and demanded correction therapy.Conclusion. A pilot study on the evaluation of bronchial provocative tests suggests that the formation of bronchial hyperreactivity in convalescents of whooping cough is probable, including without a history of atopy, which increases the risk of developing bronchial asthma, however, additional studies are required for a final conclusion.

Dysfunction of transient receptor potential ion channels as an important pathophysiological mechanism in asthma

Asthma is a chronic heterogeneous disease characterized by chronic inflammation and bronchial hyperreactivity. Neurogenic inflammation is one of the important causes of hyperreactivity. Dysfunction of transient receptor potential (TRP) ion channels underlies the development of neurogenic inflammation, bronchial hyperreactivity and respiratory symptoms of asthma such as bronchospasm and cough. TRP channels are expressed in the respiratory tract. Their activation is mediated by endogenous and exogenous factors involved in the pathogenesis of asthma. The study of functioning and regulation of TRP channels is relevant, as they could be important therapeutic targets for asthma. The aim of the review is to summarize modern ideas about the mechanisms of functioning and regulation of members of the TRP channel superfamily, the role of which in lung pathology and physiology are the best studied.