When it is difficult to assess or record a symptom because it only happens infrequently – as with blackouts – a Reveal© device can be used. The device, which is the size of a packet of chewing gum, is placed under the skin at the left shoulder. You will need to go into hospital as a day case to have this done. A small cut about 2 cm long (just under one inch) is made and the device is inserted. The device monitors the heart’s rhythm and can record any abnormal events that it is programmed to detect. If anything happens, a small box with a button can also be placed on the surface of the skin over the Reveal© device. The device may then be activated by pressing the button, causing it to record the preceding 15 minutes of the heart’s activity. The device can then be ‘interrogated’ by a computer at the hospital and the doctor can examine the recording. The device has a battery that can last up to two years if necessary.