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.
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