Dr Lyne first championed this ground-breaking device in Dublin 10 years ago – now it’s becoming the standard of care across the water
It weighs less than 2 grams. It looks like a vitamin pill. And it’s not much bigger either.
Super-small leadless pacemakers (also called wireless pacemakers) have such a tiny footprint, you could be forgiven for thinking they can’t amount to much. But in fact these little devices – which Heart Rhythm Cardiologist pioneered here in Ireland a decade ago – are starting to make big waves in the world of heart medicine.
Last month the UK watchdog NICE – one of the world’s most influential medical bodies – released its approval for using leadless pacemakers in the treatment of slow heart rhythm disorders (bradyarrhythmia), a condition that affects about 1 in every 1,000 people in Ireland.
It’s a significant endorsement for a technology that has quietly been changing lives for several years now. So what exactly are leadless pacemakers, who are they appropriate for, and what does this mean for the future of heart rhythm treatment?
What is a cardiac pacemaker?
You probably have a rough idea of how the traditional devices work. Cardiac pacemakers are little battery-powered units that a cardiologist implants underneath your skin, usually on the left side of the chest near the collarbone. The device, which is about the size of a matchbox, is then connected to the heart using one or more leads (very thin wires).
If the pacemaker detects an abnormally low heart rate, it can generate a tiny electrical pulse that travels down the leads to the heart tissue, stimulating the heart into maintaining its rate.
How is a leadless pacemaker different from a regular pacemaker?
As you will have guessed from the name, the key difference is the absence of leads. Rather than connecting the device to the heart with wires, the cardiologist inserts the pacemaker into the heart itself. Using a catheter system (a long, thin tube), the cardiologist places the unit inside the heart wall and securing it with flexible tines (tiny hooks).
Once up and running, the device can then carry out its pacemaking functions in the same way, but with a direct physical connection to the heart tissue.
What makes leadless pacemakers better for patients?
Leadless pacemakers have a few advantages over traditional devices:
Size
They are much smaller than traditional pacemakers; in fact, just a 10th of the size, on average. Because they’re placed inside the body, you won’t see or feel a bump beneath the skin as you would with a regular pacemaker, and there’s no scar on the chest. They are completely invisible.
Operation
Implanting a leadless device is a one-step procedure. The cardiologist first makes an incision in the groin, then passes the pacemaker up through a vein into the heart using a catheter (a long, thin tube). For regular pacemakers, it’s a two-stage procedure. The cardiologist creates a “pocket” for the device under the skin of the chest, then threads wires up to the heart through the vein.
Recovery
It usually takes a few weeks to recover from a regular pacemaker implantation. You have to be careful to avoid certain activities: for instance, not lifting the arm nearest your device above shoulder height for a week after the procedure; not pressing on the area where the pacemaker sits; and not lifting anything heavier than 4 or 5kg.
By contrast, you can normally resume normal activities within the first week after a leadless pacemaker implantation.
Complications
Though it’s very rare to get an infection after a pacemaker implantation, the risk is still lower with a leadless device because there’s only one incision and one small unit, rather than two incisions and a series of wires.
As the Heart Rhythm Alliance points out, this may make them particularly suitable “for people who are at higher risk of infection, have had previous device complications, or have limited access to blood vessels needed for traditional pacemakers.”
Why is NICE approval significant?
NICE (the National Institute for Health and Care Excellence) is based in the UK, but its advice influences healthcare systems in many other countries too. That’s mainly due to the extensive research that goes into their recommendations, plus the number of seasoned experts who contribute to it.
For another recent example, see our recent news story on Pulsed Field Ablation.
This latest report on leadless pacemakers examined findings from more than a million patients before drawing its conclusions. Since it’s also NICE’s “final guidance” on the topic, the approval acts as a green light for other health authorities to use the devices more widely.
Leadless pacemakers will now be rolled out across the NHS – and further afield. For those of us who have seen the difference this can make to patients for some years now, that’s great to see.
Which leadless pacemaker does Heart Rhythm Cardiologist use?
We use a leadless pacemaker called the Micra, from Medtronic. Dr Lyne first started providing implantations with this device in 2016. Dubbed the “world’s smallest pacemaker”, the Micra is said to be 93% smaller than conventional pacemakers.
The implants have an excellent success rate – 99% – and research has shown them to have fewer complications than traditional pacemakers too.
They’re also something of a local success story, proudly manufactured in Galway for more than a decade. “The first couple of years we worked on it, we were excited [by the] data,” recalls Site Leader Tom Shiel in this recent video.
“[But then] we were overwhelmed by the positive feedback that was coming from physicians, hearing how smoothly all the cases were going, how quickly they were going, how the patients were recovering so quickly, and how they were getting instant benefits.”
Am I suitable for a leadless pacemaker?
Given the potential benefits, you may be wondering: would a leadless pacemaker be a good option for my partner or me? That depends on the type of rhythm problem you have.
Primarily for slow rhythm problems
Firstly, it’s important to understand that leadless pacemakers are mainly used to treat a rhythm disorder called bradyarrhythmia (you may also hear it called bradycardia, a more general term). This is what the NICE recommendation is focused on.
A bradyarrhythmia is an abnormally slow heart rhythm. While a normal heart beats between 60 and 100 times a minute at rest, a heart with bradyarrhythmia beats much less frequently. Because the heart isn’t contracting so often, it can stop the body from receiving enough oxygen-rich blood, which can lead to unpleasant symptoms like fatigue, breathlessness, dizziness and fainting.
If left untreated, bradyarrhythmia can also increase the risk of developing more serious complications. The first generation of leadless pacemakers was designed with this rhythm problem in mind – for what we call “single-chamber pacing” in the heart’s right ventricle (the chamber that pumps blood to the lungs).
Increasingly for other heart problems too
The good news is that leadless pacing technology is becoming more available to other heart rhythm problems, too. For instance, a US company called EBR has developed a wireless device that paces the left ventricle of the heart (the chamber that pumps highly oxygenated blood to the body). Rather than helping to speed up a slow heart rhythm, the WiSE-CRT pacemaker resynchronises the heartbeat to treat heart failure.
Another family of pacemakers uses leadless technology to “talk” to a patient’s S-ICD, an implantable cardioverter defibrillator that delivers tiny electrical shocks if it detects a dangerously fast heart rhythm.
Innovations like these are bringing effective pacemaking to patients with more complicated disorders and medical needs. So, while the NICE approval is specifically aimed at slow heart rhythms, we’re expecting to see many more devices like these over the next 10 years. As ever, we’ll keep you updated on the key developments!
- You can find out more about how leadless technology is evolving in this video from Medtronic: 10 Years Advancing Leadless Pacing Together
Traditional versus leadless pacemakers
How do leadless pacemakers compare to conventional cardiac devices? Here’s a quick comparison:
| Traditional pacemaker | Leadless pacemaker | |
| Size | Typically 5cm x 7mm; about the size of a match box | About the size of an AAA battery or large vitamin pill |
| Wires | Thin leads threaded through a vein into the heart | No wires. Device sits directly inside the heart |
| Surgery | Requires a chest incision to create a surgical “pocket” under the skin | Inserted via catheter through a vein in the groin |
| Anaesthetic | Usually a local anaesthetic with a sedative; sometimes a general anaesthetic | Usually a local anaesthetic with sedation only |
| Recovery time | Usually several weeks, with some restrictions on arm movement | Usually within a week, with fewer physical restrictions |
| Visible appearance | Visible lump under the skin and a small chest scar | No visible lump and no chest scar |
| Device lifespan | Between 6 and 12 years, depending on the type of device | 16-17 years (with the latest Medtronic Micra model) |
| Pacing chambers | Available for single, dual and triple-chamber pacing | Currently more limited capability, single or dual, but evolving all the time |
Learn more about pacemakers
Looking for more detailed information about pacemakers, how they work and what it’s like to live with one? You’ll find lots more resources on the Heart Rhythm Cardiologist website, including:
Common types of pacemaker
Internal Defibrillators (ICDs)
Living with a pacemaker
Living with a Pacemaker: A Guide to Activities, Restrictions, and Everyday Life
5 key ways to look after your new pacemaker
Driving in Ireland when you have a pacemaker
Ask the Doctor: ‘Since my father got a pacemaker, he’s worried about doing anything. Are there any things he should avoid?’ (Dr Lyne answers a reader’s question in Image magazine)
Recent advances
Concerned about your heart? Get in touch with Dr Lyne at Heart Rhythm Cardiologist.
Leadless Pacemakers: FAQ
Leadless pacing technology is increasingly becoming available for other, more complicated heart rhythm problems. For instance, new wireless devices are being developed to treat heart failure and to “talk” to implantable defibrillators that detect dangerously fast heart rhythms.
