Study objective: To determine the frequency of successful cardioversion and the adverse effects of adenosine treatment in pediatric emergency department patients with supraventricular tachycardia (SVT).
Methods: This was a multicenter descriptive study with both prospective (convenience sample) and retrospective (chart review) patient entry. The setting was 7 urban pediatric EDs with a yearly census range of 22,000 to 70,000 visits. Pediatric patients 18 years of age and younger who received intravenous adenosine for presumed SVT were eligible.
Results: Six investigators from 7 pediatric EDs entered 82 patients with 98 presumed SVT episodes (52 prospective and 46 retrospective) into the study. Twenty-five episodes occurred in children younger than 1 year of age. Eight patients had congenital heart disease, 59 had a history of SVT, 43 were taking cardiac medications (digoxin in 27), 13 had a history of asthma, and 25 presented in compensated cardiogenic shock. A total of 193 intravenous doses of adenosine were administered; doses were classified as low (<.1 mg/kg [n=18]), medium (.1 to <.2 mg/kg [n=116]), or high (>/=.2 mg/kg [n=59]). The dose range was.03 to.5 mg/kg, and only 2 doses were higher than.3 mg/kg. A total of 95 patient-events were determined to be SVT, all but 5 of which were atrioventricular (AV) node-dependent; 3 events were ventricular tachycardia. The overall cardioversion success rate of adenosine was 72% (71/98), and that for AV node-dependent SVT was 79% (71/90). Cardioversion was successful for 4 patient-events at a low dose, 44 at a medium dose, and 23 at a high dose of adenosine. Adverse effects occurred in 22 patients, and no patient had bronchospasm or hemodynamically significant arrhythmia.
Conclusion: Intravenous administration of adenosine led to successful cardioversion in 72% of pediatric ED patient-events that were presumed to be SVT. A dose range of.1 to.3 mg/kg was found to be most effective. Adenosine was not associated with significant adverse effects.