REVERT Study findings

Background
Supraventricular tachycardia (SVT) is a common cardiac arrhythmia (irregular heart rhythm) affecting people of all ages. When a person suffers an attack, the heart beats very quickly producing unpleasant palpitations. People experiencing such an attack frequently attend the Emergency Department of a hospital, often concerned that they may be suffering a heart attack when in fact it is a heart rhythm problem.

The first treatment offered is usually a Valsalva Manoeuvre (VM). This is a physical treatment using a strain while blowing, like trying to inflate a balloon, which sometimes successfully slows the heart rhythm and the SVT attack stops. If the VM does not work, a drug called adenosine is usually injected into a vein to cease the irregular heart rhythm (arrhythmia); this is usually successful but has very unpleasant side effects.

It has been suggested that changing the way the VM is performed may increase its effectiveness and reduce the need for adenosine. The aim of this study was to determine whether a modified VM is more successful at restoring a normal heart rhythm than a standard VM. In the standard method the VM is performed entirely in the sitting position. In the modified version the VM is still performed in the sitting position, but then the patient is immediately laid down with their legs lifted for 15 seconds before being returned to sitting.

In ten hospitals in the South West of England, adults attending the Emergency Department with suspected SVT were invited to take part in the study. Patients were not allowed to enter the study if they were medically unstable, or in the last trimester of pregnancy, or unable to have their legs lifted for any reason.

In total, 428 individuals with SVT were recruited to the study. Of these, 214 were randomly allocated to undergo a standard VM and 214 to undergo the modified approach.

Findings
The attending doctor reviewed an electrocardiograph (ECG – heart rhythm recording) after the VM to judge whether the VM was successful or not for each patient. The heart rhythm returned to normal in 93 (44%) people using the modified VM compared with 37 (17%) people using the standard VM, suggesting that the modified technique was much more effective in returning the heart to its normal rhythm.

The modified VM was easily accommodated by patients, and resulted in a reduced need for other emergency treatments, including adenosine, compared to the standard VM.

Conclusion
The modified VM was much more effective than the standard VM and does not have any disadvantages or side effects. The technique was easy to implement and is cost-free. Therefore this has potential benefits for SVT patients worldwide. 

Healthcare professionals who treat SVT should consider using the modified VM as routine initial emergency treatment for SVT . This could save a large number of patients being prescribed a drug (adenosine) with unpleasant side effects. It is also possible that once patients have been shown the modified VM for treating their SVT they will be able to perform it themselves, therefore reducing the need to visit the Emergency Department at the hospital, and the anxiety and stress that can cause. With appropriate knowledge and confidence, some patients will be able to manage an episode of SVT at home without the need to visit the hospital at all.

If you would like further information, you can read about the study in full in The Lancet medical journal, or if you have any questions or would like further information on SVT or any cardiac arrhythmia, please contact trudie@heartrhythmalliance.org.

This project was funded by the National Institute for Health and Care Research (NIHR) through its Research for Patient Benefit (RfPB) Programme (Grant Reference Number PB-PG-0211-24145). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.