The REVERT Trial: A Modified Valsalva Maneuver to Convert SVT

Written by Salim Rezaie REBEL EM Medical Category: Cardiovascular

Background: In patients with cardiovascularly stable supraventricular tachycardia (SVT), the valsalva maneuver is recommended as an initial maneuver to help with cardioversion. The success rate of the valsalva maneuver alone is documented at 5 – 20%. The next option for patients who still remain in SVT is intravenous adenosine. Adenosine briefly stops all conduction through the AV node, which causes patients to feel a sense of doom or like they are about to die. Increasing venous return and vagal stimulation by laying patients supine and elevating their legs may increase the rate of conversion and is simple, safe, and cost effective.

The Modified Valsalva Maneuver:

Procedure: In a semi-recumbent position patients produce 40mmHg pressure for 15 seconds and then repositioned in a supine position with a passive leg raise immediately after the valsalva strain

What They Did:

Multicenter, Randomized Controlled, Parallel-Group Trial in 10 emergency departments in England

Random allocation of patients presenting with supraventricular tachycardia (SVT) in a 1:1 ratio

Modified valsalva manoeuvre vs standard semi-recumbent valsalva manoeuvre

Excluded patients with: Atrial fibrillation and flutter Patients with Systolic Blood Pressure of <90mmHg



Outcomes:

Primary: Return to sinus rhythm at 1 min after intervention

Return to sinus rhythm at 1 min after intervention Secondary: Use of adenosine, Hospital admission, Length of Stay in ED, and Adverse Events

Results:

428 patients with SVT included in primary analysis

Primary Outcome: Return to NSR at 1 min Standard Valsalva Arm: 37/214 (17%) Modified Valsalva Arm: 93/214 (43%) Absolute Difference = 26.2% NNT = 3

Return to NSR at 1 min Use of Adenosine: Standard Valsalva Arm: 148/214 (69%) Modified Valsalva Arm: 108/214 (50%)

Any Adverse Event: Standard Valsalva Arm: 8/214 (4%) Modified Valsalva Arm: 13/214 (6%) Not Statistically Significant ZERO Serious Adverse Events



Strengths:

No crossover between groups

Zero cost impact

Limitations:

Treating clinicians could not be blinded to treatment allocation

Discussion:

How many things in medicine are simple, cost zero dollars, well tolerated and have zero serious adverse events? This study is a game changer in my mind. In addition fewer patients with this intervention required the impending sense of doom drug adenosine. Why would we make our patients feel like they are about to die, when we can do this one simple intervention to try and spare that?

There was no real time saving or reduced hospital admission with the modified valsalva maneuver, but so what? Admission rate and length of stay were not increased by this maneuver either.

Just in case you don’t have a manometer at your emergency department, it turns out that if you have a patient blow into a 10mL syringe just enough to move the plunger, you will achieve a pressure similar to 40mmHg

One additional thing to keep in mind is with the modified valsalva maneuver, there is decreased resource utilization (i.e. No IV line, need for multiple nurses, and time taken)

Author Conclusion: In patients with SVT, a modified valsalva manoeuvre with leg elevation and supine positioning at the end of the strain should be considered as a routine first treatment, and can be taught to patients.

Clinical Take Home Point: In patients with cardiovascularly stable SVT, a modified valsalva maneuver should be the first maneuver attempted to convert SVT. It is simple, zero cost, well tolerated, and with zero serious adverse events.

References:

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

For More Thoughts on This Topic Checkout:

Post Peer Reviewed By: Anand Swaminathan (Twitter: @EMSwami)