A case of SVT: response to the third dose of Adenosine

Abstract

Background: Supraventricular tachycardia (SVT), manifested as rapid and regular heartbeat, is the most frequent symptomatic tachyarrhythmia requiring medical intervention in children. SVT occurs in 1 in every 250-1,000 children. The heart rate can be as high as 180 beats/minute in children and 220 beats/minute in Infants. Evidence suggests that the primary dose of adenosine should be given as 0.1 mg/kg, administered in an intravenous bolus with a dose up to 6 mg. If the primary dose is insufficient, then the amount is increased by 0.1 mg/kg-0.2 mg/kg to a maximum of 12 mg. Our case demonstrates the response to adenosine after the third dose. Case presentation: A 12-year-old boy, previously diagnosed with recurrent SVT, presented with a complaint of palpitation for the last 30 minutes. There was no obvious trigger for his palpitation on history and examination. He was conscious, well looking with normal blood pressure, and good perfusion. We started the management in accordance with pediatric advanced life support guidelines, in which we noted a partial response after the administration of the second dose of adenosine. Subsequently, a third dose of adenosine of 0.2 mg/kg was administered, terminating SVT and regaining a normal sinus rhythm in the patient. Conclusion: After reviewing recent evidence regarding stable SVT management and adenosine side effects, we found that there is no evidence limiting the use of adenosine to only two doses, especially in a case of short or minimal response following the second dose.