Long QT syndrome in children with asthma

Finding the long QT syndrome on electrocardiogram (ECG) in a patient with asthma presents a therapeutic dilemma. The treatment of choice for long QT syndrome is β-adrenergic blocker drugs that may aggravate bronchospasm. Conversely, the treatment of asthma with β-adrenergic agonists may cause arrhythmias in patients with long QT syndrome. We report our experience with three children with asthma with long QT syndrome. Patients with asthma with long QT syndrome under our direct care or on whom we have been consulted were treated with β-blocker drugs, and the effect on their asthma was observed. When required, β-agonists were administered, and the effects on cardiac rhythm were noted. All three patients developed status asthmaticus during a respiratory infection while receiving β-blocker therapy for 8-24 months. All received standard therapy for status asthmaticus with inhaled β-agonist and intravenous glucocorticoid, and one received intravenous theophylline. Only minor disturbances of cardiac rhythm were observed. Patients with asthma with long QT syndrome should not be denied treatment with β-blockers because the benefits outweigh the risks. If these patients develop status asthmaticus, they should be treated with standard therapy while receiving ongoing cardiac monitoring for arrhythmias.