Step 1: Modified Valsalva
- Have the patient lie in a semi-recumbent position and blow into a standard 10 mL syringe as long as they can.
- Lay the patient supine and elevate the lower extremities for 1 minute.
Step 2: Escalating adenosine doses
- If standard dose of 6 mg of IV adenosine fails to terminate SVT, escalate subsequent doses by 6 mg.
- Doses up to 36 mg has been successful in case reports.
Step 3: Attempt an infusion of a Calcium Channel Blocker
- Diltiazem or verapamil can be given as a slow bolus.
- Has been shown to be at least as successful, if not more successful, than adenosine in terminating SVT
- May cause hypotension – treat with fluids and/or IV calcium gluconate
Step 4: If cardioverting, use propofol as sedative
- Propofol has terminated a variety of tachyarrhythmias in multiple case series.
- Remember to administer pain medication as propofol has no analgesic effects.
- Synchronized cardioversion of SVT only requires 50 Joules as initial dose.
References:
Lim SH, Anantharaman V, Teo WS, Chan YH. Slow infusion of calcium channel blockers compared with intravenous adenosine in the emergency treatment of supraventricular tachycardia. Resuscitation 2009; 80:523-528.
Bailey AM, Baum RA, Rose J, Humphries RL. High-Dose Adenosine for Treatment of Refractory Supraventricular Tachycardia in an Emergency Department of an Academic Medical Center: A Case Report and Literature Review. J Emerg Med. 2016 Mar;50(3):477-81.
Appelboam A, Mann C, et al. Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial. Lancet 2015; 386:1747-53
