Many heart symptoms are caused by abnormal heart rhythms. If the rhythm is particularly slow, I may recommend having a pacemaker fitted. A pacemaker monitors the heart rhythm at all times, and if it sees the heart is beating too slowly, can ‘kick in’ before symptoms occur. I implant these under sedation in a cardiac catheterisation laboratory, with a nurse, a cardiac physiologist and radiographer assisting. The procedure is invasive, but serious complications are rare. One or two leads are guided into the heart via veins, and connected to a battery implanted under the skin, often near the shoulder. These devices are small, about the size of a 50 pence piece. The battery life will depend on how much it is needed, but can often be in excess of 10 years, after which it will need to be replaced using a (smaller) procedure. Patients with pacemakers need follow up in clinic to ensure correct functioning of the device.