Abstract
Continuous isoproterenol inhalation therapy (CIIT) is known to be useful in the management of children with severe asthma exacerbation. However, it has been recently reported that children develop bradycardia during CIIT. Therefore, we evaluated the changes in cardiac rhythm of children who admitted to our hospital for moderate to severe asthma attack. From April 2004 through October 2006, CIIT was performed in 47 children, whereas 49 children were treated with conventional therapies including frequent inhalation of beta2-agonist. During the recovery period, percentages of children whose heart rate became lower than normal limit were similar in both CIIT group and conventional therapy group (15%, 8%, respectively: p=0.39). In those children, only 2 of CIIT group were defined as bradycardia. All patients were asymptomatic, and all recovered spontaneously. Subsequent cardiac workup revealed catecholaminergic long-QT syndrome in one of the conventional therapy group. From our observation, bradycardia is not induced by CIIT itself, rather caused by a relative parasympathetic over-ride. However, rare cardiac complications need to be borne in mind.
