Supraventricular tachycardias (SVT) (excluding atrial fibrillation and atrial flutter) are common cardiac arrhythmias leading to presentation to the Emergency Department (ED). The Valsava maneuver is a recommended first-line method to cardiovert stable patients, but its reported efficacy is low (5-20%). Chemical cardioversion agents can have unpleasant side effects and require intravenous access. Increasing the success rate from the Valsava maneuver could lead to increased patient comfort and decreased resource utilization.
Is a modified Valsava maneuver more effective than a standard Valsava maneuver at restoring sinus rhythm in patients presenting to the Emergency Department with supraventricular tachycardias?
Patients >18 y/o with suspected SVT at ED triage (but not atrial fibrillation or flutter)
15 seconds Valsava maneuver while sitting semi-recumbent followed by 15 seconds with legs lifted at 45 degrees while lying fully supine
15 seconds Valsava maneuver while sitting semi-recumbent
Outcome (Primary): Restoration to sinus rhythm at 60 seconds after initiation of Valsava maneuver
Outcomes (Secondary): Use of adenosine, use of any emergency treatment for SVT including adenosine, need and reason for admission to hospital, length of time participants spent in ED, adverse events.
Multicenter, randomized controlled clinical trial conducted with intention-to-treat analysis. Participants and clinicians were unblinded.
Unstable with SBP < 90mmHg or other indication for immediate cardioversion, suspected atrial fibrillation or flutter, contraindication or inability to perform Valsava, or third trimester pregnancy
- Sinus rhythm at 60 seconds: 17% (standard Valsalva) vs 43% (modified Valsalva) (absolute difference 26%, p <0.0001) NNT = 3.8
- Adenosine administered: 69% vs 50% (absolute difference 19%, p = 0.0002)
- Any anti-arrythmic administered: 80% vs 57% (absolute difference 23%, p<0.0001)
- No difference in rate of discharge from ED, time in ED, or adverse events.
- 433 patients enrolled over 36 months in 10 hospitals. (5 patients recruited twice in error & excluded)
- 214 patients included in standard group & 214 in modified group
- No significant differences in baseline characteristics (including gender, age, presenting vital signs, and cardiac/medical history)
- Large, multicenter trial
- Appropriate randomization techniques
- Objective, patient centered endopoint
- Study asked a clear clinical question
- Good follow-up achieved
- Patients and study providers not blinded
- Limited degree of patient benefit (no change in adverse events, length of stay, or admission rates)
“In patients with supraventricular tachycardia, a modified Valsava 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.”
There is evidence that the modified Valsava maneuver described in this study can significantly increase the likelihood of conversion to sinus rhythm when used in stable adult patients presenting in SVT. The maneuver has the potential to decrease patient discomfort and resource utilization, and can potentially be taught to patients with recurrent episodes of SVT and prevent ED visits.
Potential Impact To Current Practice
The proposed intervention was found to be effective and has no cost. This technique can be brought to clinical practice immediately.
Evidence is shown that the modified Valsava maneuver has increased conversion rates compared to standard Valsava, and should be considered as a primary method of cardioversion for stable patients presenting in SVT.