'World's smallest' pacemaker fitted for first time in England

Prof John Morgan (left) called the new device a "milestone for cardiac rhythm management in the UK"

The world's smallest pacemaker has been fitted inside the heart of a UK patient, medics have said.

The Micra Transcatheter Pacing System was fitted for the first time in England at Southampton General Hospital.
Consultant cardiologist Prof John Morgan said the procedure was a "landmark moment".
He said the device was "not much larger than an antibiotic pill" and was one tenth the size of traditional models.

A brief history of the pacemaker

• Electrical activity within the heart was discovered in the 1800s
• The first artificial pacemaker, built by Albert Hyman in 1932, was powered by a hand-cranked motor
• Post World War 2 smaller devices were pioneered, with some worn like a necklace
• In 1958 the first implanted pacemaker was given to Arne Larsson in Sweden, but the device failed after three hours
• Early pacemaker batteries had short lifetimes until Wilson Greatbatch pioneered long-life lithium batteries in the 1970s

Source: The Science Museum, London

Currently, pacemakers, which use electrical impulses to regulate the beating of the heart, are inserted under the skin and connected to the heart via a lead.

The lead carries electrical signals to correct slow or irregular heartbeats, but they can require replacement due to broken or dislodged wires.
The new device can be implanted directly in the heart and delivers electrical impulses from an electrode, removing the need for a lead.
Prof Morgan said: "In addition to the advantages of the device's size and wireless technology, the procedure reduces the risk of infection and extended recovery time associated with traditional, more invasive surgical pacemaker implants.
"This a big step forward in patient treatment and a milestone for cardiac rhythm management in the UK."

Analysis By Fergus Walsh, BBC Medical correspondent
This new technology has several potential advantages.
Most important is the absence of a wire or lead which carries the electrical impulse from conventional pacemakers to the heart. These wires can come under immense pressure and can be a source of complications.
Standard pacemakers are implanted under the skin in the chest which can be a potential infection risk. By contrast, the tiny pacemaker used in these trials is inserted via a catheter from the groin and sits in the heart.
At 26mm long and weighing 2g, the Micra TM used in Southampton can claim to be the world's smallest pacemaker.
Southampton General is the only UK hospital which is taking part in a global clinical trial of the device.
A patient in Austria was the first to have the device implanted in December 2013. A rival system called Nanostim from St Jude Medical is also undergoing trials. It is 41mm long.
A third technology under development by EBR Systems combines a pacemaker implanted under the skin which wirelessly sends ultrasound energy to a receiving electrode - about the size of a grain of rice - implanted in the left ventricle.