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A 5yo girl comes in for chest pain for 6 hours and is noted to have a heart rate of 250 that is not varying. Review of the electronic medical record reveals a history of WPW. Mom says she has not had an episode of fast heart rate since age 3 weeks when she was first diagnosed. She is not on any medications. She is awake and alert, and her blood pressure is 85/45.
October 10, 2018 at 6:39 pm
C) Vagal maneuvers while getting antecubital IV access for adenosine 0.1 mg/kg
The patient is in SVT. The SVT is narrow complex and regular, and she is alert and hemodynamically stable, ie not hypotensive. There is time, therefore, to attempt medical cardioversion before electrical cardioversion is indicated. Patients with WPW who also have atrial fibrillation (up to 20% of WPW patients) given agents that block the AV node, such as adenosine, are at risk of rapid conduction to the ventricles through the accessory pathway, leading to ventricular fibrillation. These patients will have an irregular wide complex tachycardia. Patients like this one with a regular narrow complex tachycardia are safe to treat as for any other SVT and to give adenosine.