ABSTRACT
Background: Uncontrolled asthma (BA) can be complicated by cardiac conduction disturbances and arrhythmias. It is typical mainly for adult asthmatics patients. In asthmatics children the effect of bronchoconstriction on cardiac conduction, including the supraventricular component of the ECG, is currently under discussion. The objective of the research is to analyze ECG parameters of the atrial complex and atrioventricular conduction and to assess their relationship with spirometric indicators in children with BA. Methods: Hundred three patients with BA from the age of 6-17 years were examined. The spirometric parameters were evaluated, including the Tiffeneau index (TI): FEV1/FVC (%), according to the level of which the patient groups were distinguished. Group 1 (G1): with TI more than 85%, (n = 15); Group 2 (G2): with TI from 85 to 75%, (n = 40); Group 3 (G3): with TI <75%, (n = 48). The ECG parameters that characterize supraventricular conduction, including the PQ interval (sec) and the sPQ segment (sec), were analyzed. We had calculated relative PQ (rPQ) by the formula rPQ=PQ/PQmed, where PQ is the patient's PQ, PQmed are the median PQ values of healthy children of age selected. Results: The duration of the PQ in groups G1 and G2 was 0.13 (0.11; 0.14) s; and 0.13 (0.12; 0.14) s, respectively, which is statistically significantly less than in patients of groups G3-0.14 (0.13; 0.15] s, p = 0.01. The duration of the sPQ segment in children of groups G1 and G2 was also generally shorter than in patients of groups G3, and amounted, respectively, to 0.05 (0.04; 0.06) s, 0.04 (0.04; 0.05) s, and 0.06 (0.04; 0.07) s, p = 0.02. The rPQ increased progressively as TI decreased and amounted in G1 to 92.9 (85.7; 106.3) %, in G2 100.0 (92.9; 103.0) %, and in G3 104 (100.0; 107.7) %, p = 0.009. A statistically significant negative correlation between IT and PQ-r = -0.23, p = 0.02; with sPQ-r = -0.20, p = 0.045; and with rPQ-r = -0.25, p = 0.01 was revealed. Conclusion: A decrease in TI in asthmatics children is associated with a prolongation of the PQ. This may indicate a slowdown in supraventricular conduction in patients with uncontrolled asthma and, thus, be considered as a risk for the formation of subsequent supraventricular arrhythmias.
ABSTRACT
Introduction: The relationship between objective indicators of nasal obstruction and airflow limitation in children with bronchial asthma (BA) and allergic rhinitis (AR) has not yet been studied. Objective: To study the relationship between objective parameters of nasal obstruction and airflow limitation, determined using the methods of anterior active rhinomanometry (AARM) and spirometry in children with BA and AR. Materials and Methods: Eighty eight children and adolescents with BA and AR, boys-65.9% (58/88), were examined. The median age was 11.09 [10.42; 11.76] years. To determine airflow limitation, the following spirometric parameters were evaluated: forced vital capacity of the lungs (FVC), forced expiratory volume in 1 s (FEV1), the ratio of FEV1/FVC, and maximum expiratory flow at the point 25% of the flow-volume loop (MEF25). Data were recorded both in absolute values and in relative units (% pred). Nasal respiratory function was determined by AARM based on the total nasal airflow (TNAF) in absolute (Pa/cm3/s) and relative units (RTNAF, % pred). Results: In the general cohort and in boys but not in girls, a statistically significant direct correlation was found between TNAF (Pa/cm3/s) and absolute spirometry parameters of bronchial patency-all had p < 0.01. Also, RTNAF and relative MEF25 values (% pred) in the general cohort were R = 0.22, p = 0.04, and in boys, R = 0.28, p = 0.03. In girls, there was no statistically significant correlation between nasal respiratory function and spirometric parameters, all p > 0.05. Additional analysis of literature was conducted to ascertain that the identified gender differences were not occasional. Conclusion: The significant positive correlation of absolute values of AARM and spirometric parameters in children with BA and AR was established, which apparently reflects the physical development of children. Of all the relative indicators of spirometry, only MEF25 (% pred), which indirectly reflects the patency of small bronchi, had a distinct direct correlation with RTNAF. These patterns are clearly expressed in boys with BA. In girls with this disease, however, the relationship between nasal respiratory function and spirometric indicators seems to be more complex and requires further study.
