Your 29 year female patient arrives to Resus with a rapid heart rate of 215. Her blood pressure is 129/72. She appears pretty comfortable, however complains of mild shortness of breath and chest pain. She has no cardiac history and no previous history of cardiac arrhythmia. Her EKG from triage demonstrates SVT. As the nurses help her change into a gown and obtain IV access, you decide to help her try vagal maneuvers. Each maneuver fails and the monitor continues to show a rate of 210. Is there anything else you can try prior to adenosine administration? Well Appelboam et al seem to think so.

Postural Modification to the Standard Valsalva Manoeuvre for Emergency Treatment of Supraventricular Tachycardias (REVERT): A Randomised Controlled Trial

Background: Supraventricular tachycardia accounts for approximately 50,000 ED visits each year. It is primary treated with vagal manuevers (Valsalva maneuver), before pharmacological agents. Valsalva maneuvers are safe however they only work in about 1 in 5 patients. Current data estimates cardioversion in 5 – 20% of patients.

Question: Will a modified valsalva maneuver be superior to standard valsalva techniques to cardiovert stable SVT?

Design, setting, population:  Superiority trial; prospective randomized multi-center trial run at two teaching hospitals and eight district general (community) hospitals in the UK, patients with regular, narrow complex SVT were included, patients requiring immediate cardioversion or with hemodynamic instability were excluded. N = 433.

Methods: Patients > 18 years were randomized patients to receive either the modified or standard Valsalva in equal (1:1) proportions. Clinicians could not be blinded to treatment arms.

  • Intervention: Modified Valsalva maneuver
  • Control: Standard Valsalva maneuver

Outcomes: 

  • Primary outcome:  Whether the patient returned to normal sinus rhythm at 1 min
    • Standard Valsalva Arm: 37/214 (17%) vs  Modified Valsalva Arm: 93/214 (43%)
    • Absolute Risk Reduction = 26.2% (p<0.001) NNT = 3.8
  • Secondary outcomes
  • Use of Adenosine:
    • Standard Valsalva Arm: 148/214 (69%) vs Modified Valsalva Arm: 108/214 (50%)
    • p=0.0002, NNT 5.3
  •  Adverse Events:
    • ZERO  Serious Events

The Take away: With a NNT of just 3 people, it is well worth the 10 or so seconds it takes to try the maneuver, it can easily be attempted while your nurse prepares for IV access and adenosine administration. Also there is Zero risk. There aren’t many things in medicine that have zero risk and cost zero dollars. Peter Shearer can thank you later. Also Jeremy Kim is 1 for 1 with this technique and highly recommends it.

What the heck is a modified valsalva you ask?? 

Procedure: In a semi-recumbent position patients produce 40mmHg pressure for 15 seconds and then are re-positioned in a supine position with a passive leg raise immediately after the valsalva strain. Watch the video below to see what it looks like.

Reference:

  1. Appelboam A et al. Postural Modification to the Standard Valsalva Manoeuvre for Emergency Treatment of Supraventricular Tachycardias (REVERT): A Randomised Controlled Trial. Lancet 2015. [epub ahead of print] PMID: 26314489