QTc interval in Acute Severe Asthma

Abstract

Abstract Background Prolonged QTc interval in children may be congenital or acquired. It could be fatal if it induces tachyarrhythmias and cardiac arrest. Objectives This work studied the QTc interval in acute asthma attacks and its relation to the severity of the attack and the bronchodilators used. Patients and Methods This is a descriptive prospective study of 30 children with moderate and severe asthma. Patients were divided according to GINA guidelines 2016: Group 1:10 patients with moderate acute attack, Group Il: 20 patients with severe acute attack. 12 lead ECG was done before start of medication, then repeated daily till discharge. QTc interval measured in lead V5 using Bazett Formula was considered prolonged if > 445msec. Results Our study showed that 4 patients (13%) developed prolonged QTc interval; 3 (75%) had severe attack and one (25%) had moderate attack. QTc interval increased with number of bronchodilators used, but not reaching statistical significance. On day2, QTc was 340—435msec in patients on 2 medications and 350—460msec in patients on 3 medications. However, on 3rd day QTc interval was between 348-410msec,346—420msec,350—446msec in patients having 1, 2, 3 medications respectively. Also, there was no relation between theophylline and prolonged QTc interval. Conclusion Prolonged QTc interval can occur in 13% of children with moderate and severe asthma. QTc interval increased with number of bronchodilators used yet not reaching statistical significance. Bronchodilators must be used judiciously since they might be potentially arrhythmogenic drugs that induce fatal arrhythmia .