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Evaluation of Pre-hospital use of a Valsalva Assist Device (VAD) in the Emergency treatment of supraventricular tachycardia (SVT).


Study Overview

What are we trying to determine with this research?....

Does routine ambulance service access to a VAD and its instructions, to treat adults with an attack of SVT, reduce the rate of hospital conveyance compared to current standard care?

The research is funded by the National Institute of Health and Care Research, Research for Patient Benefit scheme and sponsored by SWASFT.

If you have any further questions about the study, please contact us at

SWASFT is committed to transparency in clinical trials and so this study is registered with the ISRCTN and can be viewed here:

A short vlog on what EVADE is - 

Information for Patients

 If you were treated by blowing into a syringe like this – please refer to this information leaflet here.

If you were treated with a device like this - Please refer to this information leaflet here

If you were treated by a South Western Ambulance Trust clinician after the 1st July 2022, a copy of this letter will be sent to your GP automatically. 

What Should I do if Symptoms Return?

SVT can sometimes return and the Valsalva manoeuvre treatment is worth trying yourself as it can often quickly stop the episode. The ambulance clinician will have left you with an empty syringe. If you feel that an episode is happening again, use this in the same way that the clinician asked you to do when they first treated you.

Following these 4 simple steps:

  1. Lie down with your back sat up, in the same position as if you were reading a book in bed.
  2. Blow into the end of the syringe hard enough to just move the plunger if you can (it might need loosening by hand to start with) and continue for 15 seconds.
  3. Immediately at the end of the strain, lay flat and rest your legs up to approximately a 45oangle on a wall, bed or chair and completely relax for 15 seconds.

  1. Try the manoeuvre up to three times. If it works and the symptoms have resolved you should inform your GP or call 111 to see if further follow up is needed. If your symptoms are ongoing dial 999.If at any stage you suffer from chest pain, shortness of breath or feel like you might pass out, dial 999 immediately.
  2. If you’re by yourself, do the best you can.

Information for Staff

EVADE steps when attending SVT in adults:

    1. Access blue Valsalva pouch in large drugs bag side zipped pocket
    2. Depending on the study phase the pouch may contain a syringe or VAD, please use whatever is in the pouch to assist the modified VM
    3. Leave Patient Information Leaflet with patient, and complete incident number on the front (also in pouch)
    4. Leave VAD with the patient
    5. Document in the research tab in EPCR EVADE and patient information leaflet left.
    6. Treat as usual and in accordance with SWASFT clinical guidelines.

Please contact your station champion for study-related questions or contact the Lead Research Paramedic at

The EVADE study training can be revisited at any time.

Scan the QR Code to view the SVT Training video or visit this link 

How can I find out about the results of the study?

Once the study is completed, the results of the study will be posted on the website of the Arrythmia Alliance, a patient charity and our partners in this research. This website also contains support and help for people who suffer heart rhythm problems and can be found here:

If you have a question regarding SVT which is not directly about the study, please contact your GP.

Contact Us

If you have any further questions about the study, please contact us at 

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