Watch the 500,000th pacemaker operation - Mark Gallagher, a Consultant Cardiologist, talks through the procedure.
The 500,000th pacemaker operation in the UK has taken place - at the same hospital, St George's, London, which carried out the first such procedure in 1958.
However, experts warn that although the UK was one of the first countries in the world to start implanting pacemakers, it has now fallen behind other European nations in the use of the devices.
Mrs Trudie Lobban, founder of the Arrhythmia Alliance, said: "Although implants have increased in the UK by 5% each year, we need an increase of 15% per annum to be in line with European implant rates by 2016."
She added: "100,000 sudden cardiac deaths occur in the UK every year, yet 80% of these could possibly be avoided if diagnosed and treated appropriately.
Pacemakers over the years - the very first to the most recent
"While the device costs approximately £15,000, which is a large start-off expense, over the long term they pay their way when compared to a lifetime on drug therapy and restoring the patient's quality of life.
"New technology has further helped reduce costs, doctors are now able to monitor patients remotely via a telephone link reducing the number of follow-up visits to the clinic."
Old and new
Communication technology is just one of the advances of today's pacemakers.
Previously the size of the devices meant they had to be worn, normally around the neck, with connecting wires into the heart to deliver electrical impulses. The earliest pacemakers were even plugged into mains electricity, leaving patients stuck in hospital and at the mercy of the electricity supply.
The first implanted pacemaker in the UK was the size of a pram wheel. Now devices are smaller than a matchbox and weigh between 20 - 50g. Today, pacemakers are software-controlled, allowing them to be programmed from a small external computer and their batteries last seven years without a recharge.
The 500,000th fitting was one of the latest generation of pacemakers, a biventricular ICD. It was received by Karl Sidhu from Camberley, Surrey, to resynchronise his heart muscle function, which was not working as well as it should after a series of heart attacks.
The beginning - a wearable pulse generator from 1958
As well as preventing his heart from going too slowly, the pacemaker will improve co-ordination between the upper and lower chambers, and right and left sides of the heart.
David Ward, the senior consultant cardiologist at St George's Hospital, said: "Implanting pacemakers has become almost routine in the UK, but there is nothing routine about it for patients.
"Mr Sidhu represents one of the tens of thousands of people in Britain who have had their lives improved thanks to a pacemaker and this milestone should be celebrated."
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