Objective: To assess the safety, efficacy, and diagnostic usefulness of iv adenosine in treating acute episodes of paroxysmal supraventricular tachycardia in critically ill infants and children with congenital heart disease.
Design: A consecutive sample study over a 1-yr period.
Setting: A six-bed pediatric cardiac ICU at a tertiary care center.
Patients: Nine consecutive critically ill infants and children with congenital heart disease, either awaiting emergent surgery or in the immediate postoperative period, who had at least one episode of tachyarrhythmia treated with iv adenosine.
Interventions: In children less than 50 kg, adenosine was administered in incremental doses of 100, 200, and 300 micrograms/kg every 3 mins. Patients weighing greater than 50 kg were given doses of 6, 12, and 18 mg iv. The adenosine protocol was stopped when the arrhythmia was terminated or a mechanism of the arrhythmia was shown that would not respond to adenosine administration.
Measurements and main results: Adenosine was used 14 times in nine patients, all of whom were hemodynamically unstable before or after the development of the tachyarrhythmia. Adenosine was effective in rapidly terminating all nine episodes of paroxysmal supraventricular tachycardia, six of which occurred in patients known to have Wolff-Parkinson-White syndrome. All patients had marked hemodynamic improvement after conversion to normal sinus rhythm. In five episodes of tachyarrhythmia that did not respond to adenosine, the transient block at the atrioventricular (A-V) node helped determine the underlying arrhythmia without clinically important side-effects.
Conclusions: Adenosine can be used safely and effectively in critically ill infants and children with congenital heart disease and perioperative tachyarrhythmia. More investigation into the "chemical conversion" of paroxysmal supraventricular tachycardias as well as its diagnostic value in this subset of critically ill patients is warranted.