Key Results: There were 428 adult patients included in the study. The mean age was in the mid-50s, approximately 60 percent were female, and about half had a history of SVT.
The modified Valsalva maneuver resulted in an increased frequency of conversion out of SVT to sinus rhythm compared to the standard Valsalva maneuver. The adjusted odds ratio = 3.7 (95 percent CI, 3.3–5.8; P<0.0001). Number needed to treat (NNT) = 4 (95 percent CI, 3–7).
Primary Outcome: Return to sinus rhythm at one minute:
Modified 43 percent versus standard 17 percent, NNT = 4
There was less use of adenosine and anti-dysrhythmic drugs. There was no difference in length of stay in the ED, discharge home, or adverse events.
The modified Valsalva maneuver resulted in an increased frequency of conversion out of SVT to sinus rhythm compared to the standard Valsalva maneuver.
- This pragmatic study was very well done and addressed a common condition presenting to the ED. The postural modification of the standard Valsalva maneuver represents an inexpensive, well-tolerated treatment option with a NNT of 4.
- Blinding was a potential limitation in this study. The authors tried hard to minimize this type of bias. It was not possible to blind the providers to the treatment group. However, the patients were not aware of which treatment was the modified technique. The independent cardiologist who retrospectively assessed the ECGs was blinded to group allocation. If there were disagreements about ECG interpretation between the unblinded treating physician and the blinded cardiologist, an independent electrophysiologist, also blinded, arbitrated.
Bottom Line: To REVERT your next stable patient with SVT to a sinus rhythm, consider a postural modification of the standard Valsalva maneuver.
Case Resolution: You use the modified Valsalva maneuver and successfully convert him to a sinus rhythm.
Thank you to Dr. Robert Edmonds, a third-year emergency medicine resident at the University of Missouri at Kansas City, for his help on this review.
Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.
- The REVERT trial: Dip or doom for the SVT in the emergency department? St.Emlyns Web site. Accessed April 19, 2016.
- The REVERT trial: a modified Valsalva maneuver to convert SVT. Rebel EM Web site. Accessed April 19, 2016.
- Postural modification to the standard Valsalva manoeuvre for emergency treatment of supraventricular tachycardias (REVERT): a randomised controlled trial. The Bottom Line Web site. Accessed April 19, 2016.
- This is a SVT and I’m gonna REVERT it – using a modified Valsalva manoeuvre. The Skeptics’ Guide to EM Web site. Accessed April 19, 2016.
- Smith GD, Dyson K, Taylor D, et al. Effectiveness of the Valsalva manoeuvre for reversion of supraventricular tachycardia. Cochrane Database Syst Rev. 2013 Mar 28;3:CD009502.