Bronchial asthma is a common respiratory disorder among children, worldwide. Asthma is characterized by chronic inflammation and remodeling of the airways induced by recurrent exposure to hypoxemia that leads to repeated tissue injury and repair. The interaction between respiratory diseases and cardiovascular function is complex . Cardiac dysfunction can be attributed to pulmonary hypertension (PH) secondary to recurrent hypoxia in patients with bronchial asthma. PH affects the pulmonary vasculature by releasing various cytokines leading to pulmonary vasoconstriction and enhancing the remodeling process with muscularization and proliferation of the vascular media and intima . Other hypotheses concluded that the exaggerated respiratory efforts may raise the intrathoracic pressure and increase right ventricle (RV) afterload and consequently RV hypertrophy and/or dilatation . Children with severe bronchial asthma can experience cor pulmonale later in life, but little is known about the early cardiac changes that might be present during childhood especially for mild or moderate persistent asthma. Some studies have reported right ventricular dysfunction as the earliest hemodynamic change among those cases . Other studies did not report these results and reported impaired systolic function of the left ventricle (LV) even before diastolic dysfunction . Insufficient control of BA, in turn, can cause the formation of various pathological conditions. For example, there are studies showing the risk of cardiac arrhythmias and conduction disorders in patients with uncontrolled BA due to functional changes or pathological remodeling of the myocardium . Atrial remodeling, which is the pathomorphological basis of serious supraventricular cardiac arrhythmias, has a more rapid progression with poor BA control and is formed as a result of excessive stretching of the atrial wall, as well as other adverse factors . The connection between BA and supraventricular arrhythmias, including atrial fibrillation (AF), was noted in studies by Cepelis et al. Available data indicate that in the adult population, cardiac arrhythmias are significantly more common in patients with BA than in those without it (9). The results of a Norwegian population study HUNT study, demonstrate that the risks of supraventricular arrhythmias and AF are increased in patients with an uncontrolled BA . Electrocardiography (ECG) is the universal screening method for assessing the state of the atrial myocardium and the conducting system of the heart. According to German et al. ECG analysis can make a significant input to the assessment of the risk of formation of supraventricular rhythm and conduction disorders. Therefore, the analysis of the atrial component of the ECG, and atrioventricular conduction in patients with BA is an important component of the management of these patients, especially in pediatric practice. Consequently, the study of the characteristics of the ECG and its supraventricular component in children with BA is relevan

Inclusion Criteria:

• 1. Age range: 5-18 years 2. Confirmed diagnosis of bronchial asthma, made in accordance with current international and national consensus documents

Exclusion Criteria:

• . Known congenital heart disease 2. Presence of acute infectious diseases and fever 3. Diabetes 4. Autoimmune disorders 5. Primary immunodeficiency 6. Cancer 7. Current use of oral glucocorticoids 8. Other chronic respiratory conditions 9. Systemic diseases affecting the cardiovascular system