A 12-month-old male with no significant PMH, born at full term, presents to the emergency department with cough and congestion. The nurse tells you that the heart rate is “too fast to count.”
EKG shows supraventricular tachycardia.
Patient is otherwise stable, with normal vitals. He is well appearing and interacting normally with parents and physicians in the room. Adenosine is administered twice but his rhythm does not break.
Suddenly, the patient then becomes unstable. Synchronized cardioversion is delivered. The patient’s mentation improves and EKG shows a normal sinus rhythm. Everyone breathes a sigh of relief. The patient is admitted to pediatrics for further management and workup.
Take Away #1
Non-pharmacologic options to break stable SVT
Ice pack to face
Face immersion in cold water for 30 seconds
Ask older child to blow into the end of a 10 cc syringe
Modified vagal maneuver with elevation of legs
Hold child upside down for 30 seconds? – shown to be effective (but something parents won’t love to see)
Handstand? - can also be effective with older children
Take Away #2
Medications to break stable SVT
Adenosine: 0.1 to 0.2 mg/kg
Other pharmacologic options
Procainamide 15 mg/kg IV over 30 to 60 minutes
Shown to be more effective than amiodarone
Take Away #3
Unstable SVT = SYNCHRONIZED Cardioversion
Important to make sure that machine is set to synchronized cardioversion
0.5 to 1 J/kg up to 2 J/kg
If requiring repeated shocks, remember to reset machine back to synchronized cardioversion
Alison Rosser, MD is a current first year resident at Stony Brook Emergency Medicine.
References:
https://pedemmorsels.com/upside-down-vagal-maneuver-for-svt/
Bronzetti G1, Brighenti M2, Mariucci E1, Fabi M3, Lanari M3, Bonvicini M1, Gargiulo G4, Pession A5. Upside-down position for the out of hospital management of children with supraventricular tachycardia. Int J Cardiol. 2018 Feb 1;252:106-109. PMID: 29169907.
Edited by Bassam Zahid, MD