Evaluation of Cardiac Biomarkers and Ventricular Function in Asthmatic Children

Severe acute asthma which is defined asthma that is uncontrolled despite maximal optimized therapy and treatment of contributory factors, or that worsens when high dose treatment is decreased(1) and it is characterized by severe respiratory distress because of increasing bronchoconstriction, leading to ventilation perfusion mismatch, hypoxia, respiratory muscle fatigue, carbon dioxide retention and respiratory acidosis(2) In acute severe asthma, the use of beta 2 agonists, together with hypoxia and tachycardia might cause increased myocardial workload further leading to myocardial infarction(3). Cardiac biomarkers including Brain Natriuretic Peptide (BNP),Troponin I (TnI) and Creatine kinase muscle/brain(CK-MB) are used to detect myocardial injury(4). The objective of the present study was to find out the incidence of myocardial dysfunction in patients of acute severe bronchial asthma based on cardiac biomarker levels at admission and to see whether the myocardial dysfunction was transient or persistent even after the stabilization of the patient. As far as it could be reviewed, no study relating BNP levels in pediatric asthma patients could be found in literature. Echocardiographic changes in bronchial asthma regarding RT ventricular and Ltventricular function will be assessed According to some studies right ventricular (RV) systolic and diastolic dysfunction were detected, even in mild cases, by echocardiography. On the other hand, left ventricular (LV) dysfunction usually presents itself in severe asthmatic cases which may be reversible in acute conditions (5). Some studies showed that there were no differences in echocardiographic findings regarding the ventricular function with the exception of RV wall thickness (6). Asthma affects ventricular contractility in children. Although cardiac systolic function was found to be impaired in asthmatic patients, contrary to the literature diastolic dysfunction didn't observed in these patients even by tissue Doppler imaging, may be due to using inhaled corticosteroid(7). This was one of the most comprehensive studies among asthmatic patients. Further studies with larger sample sizes or without using corticosteroid treatment war ranted to better elucidate the cardiac function.