Long QT Syndrome In Neonate - The Management Challenges In Case Of Bronchiolitis

Background

Long QT syndrome (LQTS) is a disorder of ventricular myocardial repolarization characterized by a prolonged QT interval on electrocardiogram (ECG) that can lead to ventricular arrythmias and an increased risk of sudden cardiac death. LQTS may be congenital or acquired. The gold standard therapy is b-blockers, usually propranolol or nadolol. In patients with LQTS, b₂ agonist therapy is associated with an increased risk of cardiac events.

Case presentation summary

An 1-month old boy, with personal history of congenital LQTS, family history of congenital LQTS type 2 and pending genetic study, with prescribed propranolol but failure to adherence (his mother decided no to follow the prescription), was admitted to the pediatric department due to acute bronchiolitis. On his second day of hospitalization there was a clinical worsening, with respiratory effort, prostration and feeding difficulties. He presented with type 1 respiratory failure and signs of dehydration. Promptly initiate oxygen therapy but he maintained signs of respiratory distress and hypoxemia. Due LQTS, it was not possible to prescribe nebulized salbutamol or adrenaline, so it was decided transfer to the Intensive Neonatal Unit Care to high flow nasal cannula (HFNC) therapy. There was favourable clinical outcome: he required HFNC during four days, maximum flow of 7L/min and humidified O₂ concentration of 30%, general condition improved and appetite increased. He remained hemodynamically stable, without any cardiac event. There was a positive rapid test for respiratory syncytial virus.

Learning Points/Conclusion

Bronchiolitis is one of the most common infection during the first two years of life. The general management include, in mild to severe forms, bronchodilators as salbutamol or adrenaline. In this case, due to LQTS, those drugs are not recommended and there are very limited therapeutic options.

In resume, we would like to highlight the challenging in the management of a mild bronchiolitis in case of infants with LQTS.