Living with atrial fibrillation
AF is an irregular and often fast heart rhythm. It is the most common heart rhythm disturbance and affects around one million people in the UK. Doireann Maddock explains.
Mike Butler, 67, a farmer from Evesham, Worcestershire, had his first warning there might be a problem with his heart when he was in his 30s. He was scuba diving at night, 80ft under water. “It came on as a very rapid and irregular heartbeat but I put it down to being nervous from the diving,” he says. “It went away by itself and I put it out of my mind but a few weeks later it came back again. This time I was at home and it didn’t go away by itself. The next thing I knew I was in the cardiac unit.”
Normally the heart’s natural pacemaker sends out regular electrical impulses. Atrial fibrillation (AF) happens when impulses also fire off from different places in the atria (the top chambers of the heart) in a disorganised way. These impulses override the heart’s natural pacemaker, which can no longer control the heart rhythm, causing your pulse to be irregular.
A rapid and irregular heartbeat like Mike experienced is one of the more obvious indicators of AF and it often prompts people to seek medical attention. Other symptoms can include breathlessness, tiredness, dizziness and feeling faint. Some people experience mild symptoms, and others may be unaware of any.
Initially Mike’s AF came and went. “At first it would just happen now and again and wasn’t too much of a problem, but over the years it got worse until eventually I was in AF all of the time,” he says.
This is not unusual, as Consultant Cardiologist Professor Paulus Kirchhof from the University of Birmingham explains. “Initially, AF often comes and goes without warning and long periods of time may pass in between episodes. Over time this often changes. We tend to categorise AF into three categories, which also relate to the progression of the condition. In paroxysmal AF it resolves in less than seven days without any treatment; persistent AF is when it lasts for longer than seven days (or less when treated) and longstanding persistent AF is when it has continued for more than a year.”
Common causes of AF
The exact cause of AF is not fully understood, although age is a factor. It also affects certain groups of people more than others. Professor Kirchhof explains: “We know that people with cardiovascular problems such as high blood pressure, coronary heart disease, heart failure and heart valve disease are more likely to develop AF, but we don’t really know the exact causes of it in different patients.”
In the early days I tried several different types of medication to help my heart rhythm
Genetics may also play a part, especially if you develop AF before the age of 60–65. This is an area that Professor Kirchhof is currently researching with the help of a £1,210,736 grant from the BHF.
The impact of AF can be far-reaching. “It becomes more common with age, and with our ageing population the number of people with AF in the UK could double or triple in the next 20–30 years,” says Professor Kirchhof. “This is a real concern because AF is the strongest individual risk factor for stroke and around every fourth stroke that happens is due to it.”
AF increases the risk of stroke because the irregular activity in the atria allows blood to pool in the heart. When blood pools, it tends to form clots which can then be carried to the brain, causing a stroke.
“Clots that form in the left atrium can potentially be quite big and if pumped out can lodge in a large vessel in the brain causing significant and permanent damage,” says Professor Kirchhof.
It’s also a concern that, over time, persistent AF can lead to a weakening of the heart muscle, causing it to pump less effectively. With the right treatment, these risks can be significantly reduced.
Common treatments for AF
There is currently no cure for AF and the way it is treated is individualised to the patient’s needs. It may involve medication (both to prevent a stroke and to control the heart rate or rhythm), cardioversion (when the heart is given a controlled electric shock with the aim of restoring a normal rhythm) and catheter ablation (this works by scarring or destroying tissue in the heart that triggers the AF). Having a pacemaker fitted to help the heart beat regularly may also be an option for some people.
Mike has experienced a wide range of treatments over the years. He received cardioversion on five separate occasions, has taken different combinations of medication and most recently had two catheter ablations. “In the early days I tried several different types of medication to help my heart rhythm and eventually we settled on the combination of amiodarone and sotalol. I also took warfarin to help protect me from having a stroke,” he says.
The amiodarone and sotalol worked well for Mike until about four years ago, when the AF became longstanding and persistent. At this point his cardiologist suggested an ablation.
Since the second ablation I feel great; the lethargic feeling is completely gone
Catheter ablation is often used when medication has not been effective. Mike needed two ablations about 12 months apart. “After the first one, I spent around six months in sinus rhythm but then went back into AF. I had my second ablation almost a year later and I’ve remained in sinus rhythm ever since,” he says.
Requiring more than one ablation in order to achieve sinus rhythm is common, Professor Kirchhof says. “In people without other structural disease of the heart who may not have had AF for a long time the success rate after catheter ablation at one year is about 80 per cent, with patients having up to three ablations.
“If you look at those patients five or six years later the recurrence rate is about 50 per cent. So, although we have to accept that at some point many patients will have a recurrence of their AF, the period of time without it can be very valuable, especially if there were bad symptoms because of the AF.”
Although Mike often felt tired during the years he had AF, as a keen cyclist he tried to keep as active as possible. It wasn’t always easy. “I often felt very drained, just really lethargic, and cycling was an effort,” he says.
“But since the second ablation I feel great; the lethargic feeling is completely gone and I get out on my bike as much as possible.”
Mike’s love of cycling has also led him to support the BHF in the London to Brighton bike ride five times.
Find out how to check your pulse
Professor Paulus Kirchhof on his BHF-funded research
The BHF has recently awarded Professor Kirchhof a Senior Clinical Research Fellowship worth £1,210,736 to bring his AF research and clinical work together and establish a world-leading research programme in Birmingham.
The research is focused on unravelling how a faulty gene may lead to AF. “We know that alterations to DNA near a gene called PITX2, which is required for development of many structures in the embryo, are linked with early development of AF and we’ve found that usually the left atrium has high levels of PITX2,” says Professor Kirchhof, who will now study why this is important, and whether alterations in the PITX2 gene can lead to AF.
Professor Kirchhof hopes that when we learn more about the different causes of AF, we may discover alternative treatments. “We have learned a lot in the last 20 years and we have tools in hand such as medication and catheter ablation to treat these electrical changes, but we need to go one step beforehand to understand why someone with a certain genetic predisposition develops AF. So we still have a lot of missing links and this is where research like this comes in.”
The impact of the research could be far reaching. Professor Kirchhof says: “I think and hope that we may be able to develop completely new ways to treat patients with this genetic predisposition once we have our insights. I’m very grateful to anyone who has donated to the BHF for their support in this important piece of research.”