Focus on: Pacemakers
These heart-saving devices have been around since the 1960s, but today's sophisticated models can be programmed to your needs. Judy O'Sullivan talks to a heart specialist.
Around 25,000 people in the UK have a pacemaker fitted each year - that's nearly 500 a week. The job of this clever, matchbox-sized device is to drive the heart when its natural pacemaker mechanism has failed, causing it to beat too slowly. It can also be used if the heart's main pumping chambers are beating inefficiently.
It consists of a box with a battery and computerised device, and a choice of one, two or three leads. The box is implanted under the skin just below either shoulder, usually the left, and the leads deliver electrical impulses to stimulate the heart to contract and produce a heartbeat.
The pacemaker sets the pace of the heart, but it can't restart it if it stops beating.
There are several types depending on your needs:
A standard pacemaker
This has one or two leads and is used to treat conditions such as heart block or slow heart rate.
Cardiac resynchronisation therapy (CRT)
This is a more sophisticated pacemaker with three leads used to improve the pumping efficiency of the heart muscle in heart failure patients, when the main pumping chambers beat out of time with each other. Some CRT devices also have an Implantable Cardioverter Defibrillator (ICD) function (see below).
Implantable cardioverter defibrillators (ICDs)
These deliver an electric shock to kickstart the heart. They're used for people at risk of a life-threatening heart rhythm disturbance such as ventricular tachycardia or ventricular fibrillation. Some also have a pacing function as part of the device.