A 6 week old infant is brought to the ED by ambulance for lethargy

Perform synchronized cardioversion

Perform synchronized cardioversion. The infant in the vignette has unstable supraventricular tachycardia and has already received two doses of IV adenosine without improvement. In this scenario, rapid synchronized cardioversion is the most appropriate immediate next step. This patient is experiencing unstable SVT because she is minimally responsive and hypotensive, in addition to the ECG tracing of a narrow complex tachycardia without p-waves. This patient needs assessment for hypoglycemia and other electrolyte abnormalities, but this would not be the next immediate step. Similarly, the infant may deteriorate to pulseless arrest and require cardiopulmonary resuscitation, but in this scenario, synchronized cardioversion would be the next best step. [Topjian 2020; F&L pp 601-606]