The world's smallest ever pacemaker has been implanted in a patient at Southampton General Hospital in the UK.
The Micra Transcatheter Pacing System is just one tenth the size of traditional pacemaker models - about the size of a pill.
Currently, pacemakers are usually inserted under the skin in the chest and are connected to the heart by a lead that regulates the patient's heartbeat using electrical signals.
One downside to traditional pacemakers is that the lead may become broken or dislodged, which requires the pacemaker to be replaced.
However, the new pacemaker does not require any wires, delivering electrical impulses instead via an electrode. This not only minimizes the chance of the device becoming ineffective, but it also allows the device to be so much smaller than previous designs.
The Southampton procedure is not the first time a human patient has been fitted with the Micra Transcatheter Pacing System. A patient in Linz, Austria, received the device in 2013 as part of the Medtronic global pivotal clinical trial, which involves 780 patients at 50 centers around the world.
Fast facts about pacemakers
- More than 4 million people around the world currently have a pacemaker
- Around 700,000 patients receive a new pacemaker each year
- In 2012, studies investigated powering pacemakers using the beating of the patient's own heart, which would eliminate the need for the devices to be replaced when their batteries run out.
"While pacemakers have saved countless thousands of lives over the past 7 decades since the first devices were implanted, one of the major drawbacks has been complications related to the pacing lead that is put in to deliver electrical impulses to the heart," explains consultant cardiologist Prof. John Morgan, who performed the procedure at Southampton General Hospital.
"Now we have pacemakers that are so small - not much larger than an antibiotic pill - they can be attached directly to the inside of the heart, all the problems related to the old-fashioned pacemaker lead are abolished."
Unlike the old pacemakers, which were only connected to the patient's heart via the electrical wire, the new devices are attached directly to the heart using small tines. The device is delivered by a catheter that is passed up through the groin, which also has the benefit of not leaving a scar or visible protrusion of the pacemaker under the skin.
Prof. Morgan describes the first implantation of the device as a landmark moment in cardiac rhythm management:
"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."
In March this year, a study called "LEADLESS" investigated the possibility of a battery-sized, wireless pacemaker that could be implanted into the heart.
This pacemaker was successfully implanted in 32 patients. However, another patient who was fitted with the pacemaker experienced complications during the procedure and later died from a stroke.
Subsequently, the LEADLESS II clinical trial was launched across 50 centers in the US and Canada, testing the device in 670 patients.
Written by David McNamee