Ambulatory ECG monitor versus standard care in acute unexplained syncope (sudden loss of consciousness also known as blackout or fainting)

You may be able to join this study if you are 16 or older and recently visited an emergency department or hospital unit because of a sudden blackout, but initial tests could not find a clear cause. You must live locally within the participating NHS health board area and have had fewer than five blackouts in the past month.

You will not be able to participate if doctors have already found an obvious reason for your faint. Common known causes include simple fainting (like feeling faint from heat, needles, or standing too long), a sudden drop in blood pressure when standing, an epileptic seizure, low blood sugar, a head injury, or drinking alcohol. People who have had five or more blackouts in the past four weeks, or who cannot give informed consent, are also excluded.

Taking part lasts for two years and starts while you are in hospital. A computer randomly places you into one of two groups. If you are in the first group, a nurse or doctor will fit a small heart monitor to your chest to wear for up to 14 days at home, alongside standard hospital care. If you are in the second group, you will receive standard hospital care, which might include normal follow-up appointments or routine heart tests.

After leaving the hospital, you do not need to attend extra hospital visits just for the study. Instead, researchers will contact you once a month by text, email, or telephone to answer two quick questions about your health. You will also be asked to fill out a short questionnaire about your daily life and well-being at the start, after one year, and after two years.