Diagnostic use of adenosine in two pediatric patients.

We describe the successful diagnostic use of adenosine in two pediatric patients. In the first case, adenosine infusion enabled exclusion of accessory pathway conduction in a patient who had previous evidence of Wolff-Parkinson-White syndrome. In the second case, adenosine infusion aided in the diagnosis of a nonreciprocating reentrant atrial tachycardia in a postoperative Fontan patient. The transient atrioventricular nodal blocking effect of adenosine added diagnostic certainty which was not apparent from the surface 12-lead electrocardiograms or rhythm recording in both patients. As the therapeutic use of adenosine for reciprocating supraventricular tachycardia in children becomes more popular, clinicians should also recognize the situations in which its use may facilitate diagnosis of other supraventricular rhythms.