Lee Pemberton, 31, had spent a wonderful weekend at a friend’s wedding. But the next day he felt terrible. He put it down to a mild hangover. But as time wore on, “I felt faint and light-headed. My heart began racing so my whole body shook with every heartbeat. It felt like I’d been running but I hadn’t done anything strenuous. I managed to call a friend who lives nearby to take me to my local urgent care centre. When I got to the end of the path my arms and legs seized up and I collapsed.”
He was transferred to the Leicester Royal Infirmary where it was discovered he had atrial fibrillation (AF), a potentially dangerous heart rhythm disorder where blood doesn’t flow normally through the heart.
Atrial fibrillation affects around 1.5 million people in the UK and is a major cause of stroke (when a blood vessel that supplies blood and oxygen to your brain becomes either blocked or ruptured). Signs include palpitations, breathlessness, fatigue and dizzy spells.
After arriving at hospital, Lee’s heart rate had raced to 236 beats per minute (the normal rate is between 60 and 100bpm) – and he lost consciousness. “I think I did ‘go’ for a few minutes but they used the defibrillators to bring me back.” He remained in hospital for two days but, just as he was about to be discharged, he felt awful. “At around 11pm, my whole body went heavy; I felt like bricks were attached to my arms and legs. I felt the muscles in the left side of my face being pulled down tightly.”
Doctors initially thought he was having an anxiety attack, but CT scans confirmed Lee had suffered an Ischaemic stroke (when an artery supplying blood to your brain is blocked by a blood clot). He was kept in hospital for 10 days, then underwent physiotherapy and other rehabilitation.
Six years on, he’s recovered well physically. He takes blood thinners and had a pacemaker fitted to cope with his atrial fibrillation, but still suffers from extreme fatigue, mild memory loss and mental health issues “which can affect me on a daily basis”.
Lee, now 37, is not alone in suffering from atrial fibrillation. Latest figures from the British Heart Foundation (BHF) show that the numbers diagnosed with the condition have risen by 500,000 since 2013. “Between a quarter and a fifth of strokes are due to atrial fibrillation,” says Dr Martin Lowe, a consultant cardiologist and electrophysiologist who specialises in the treatment of arrhythmias in adults and children, and works at Barts Heart Centre and Harley Street Clinic.
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.
“The two biggest risk factors for having a stroke are high blood pressure and atrial fibrillation,” says Dr Richard Francis, head of research at the Stroke Association.
“The population is ageing and we know AF is more prevalent in the elderly population,” says Professor Christopher Aldo Rinaldi, a consultant cardiologist with the Heart, Vascular & Thoracic Institute at Cleveland Clinic London and a consultant cardiologist and professor of Electrophysiology at Guy’s & St Thomas’ Hospitals. “There are other risk factors that predispose to atrial fibrillation which are increasing, including high blood pressure, coronary heart disease, heart failure and kidney disease.”
‘I often woke up feeling tired’
At 31, Lee appeared fit and well but a possible tell-tale sign was his heavy snoring. “I often woke up feeling tired.” A new study shows that people aged between 20 and 50 with sleep apnea are 60 per cent more likely to have a stroke within 15 years.
The study by Stanford University, presented at the European Society of Cardiology Congress in Amsterdam this month, followed the health records of 1.7 million American adults aged 20 to 50, a fifth of whom had obstructive sleep apnea (OSA).
The condition, which causes the airway to block during sleep, leading to loud snoring and gasping for breath on waking, is thought to affect up to 8 million people in Britain, with about 1.5 million suffering a moderate to severe form.
The study found those with the condition were 60 per more likely to have a stroke in the next 15 years – at the average age of 45. In Britain, one in four stroke patients is under 65.
And a second linked study of 766,000 people in the same age group found that those with OSA were five times more likely to develop AF, raising the risk of heart attack and stroke.
Having OSA was a much bigger risk factor than other health issues with a known link to the heart problem, including chronic kidney disease and smoking, the study found.
“When you are unable to breathe, it raises the pressure in the lungs until you ultimately wake up gasping for breath. That puts a pressure load on the heart, which causes stretch in the heart chambers, and that could cause the atrial fibrillation,” says Sanjiv Narayan, a professor of cardiovascular medicine at Stanford and the study’s author.
Chronic snoring is often dismissed as trivial or even comical. But sleep apnea, which repeatedly interrupts breathing during sleep, triggering a fall in blood oxygen levels and poor quality of sleep, is actually a major heart health “red flag”.
“It’s increasingly recognised as a very serious medical condition linked with high blood pressure, diabetes, even mental health issues on the basis that if you don’t get a good night’s sleep, and you’re tired during the day, that affects your mood,” Lowe says. “And given that link with atrial fibrillation, which is my particular field, it’s become the most important risk factor we see.
“One of the issues with Covid and remote consultations by telephone is we don’t always see our patients. If you can see a patient in clinic it’s pretty obvious if they’ve got a BMI greater than 30, you can give them specific counselling about the benefits of weight reduction. But increasingly we are missing this as doctors doing telephone consultations.”
Scientists have known that sleep apnea is an independent risk for some time. “What’s new is that sleep apnea, which is associated with a risk of AF, itself is such an important factor in terms of the ethology of strokes in a relatively young population,” Lowe says.
“Given the current obesity epidemic in the UK, at least a quarter of people are obese and probably if we’re very strict about it, about two-thirds [are] overweight. And given that one of the main risk factors for sleep apnea is obesity, then are we storing ourselves up for a huge increase in the risk of AF and stroke going forward? Not that everyone with sleep apnea is obese, but it’s a recognised association along with alcohol excess, smoking, etc.”
Obviously not all those who snore have sleep apnea, but the study suggests having the condition is a strong predictor of whether younger people will develop AF.
Lifestyle factors
What remains troubling is the sheer number of people who are unaware, like Lee, that they are living with a heightened risk of having a potentially fatal or life-changing stroke.
In severe cases, patients are given a breathing machine called a continuous positive airways pressure (Cpap) machine to keep their airway open at night.
But sleep apnea is eminently treatable through lifestyle changes, says Lowe, such as losing weight, giving up smoking and cutting down on alcohol.
“The patients I see with AF often have a very intense lifestyle from a work point of view, with lots of work stresses, combined with less exercise than they would have taken 20 years ago, and all the things that go with stress that may include alcohol excess, etc,” Lowe says. “There’s an association between sleep apnea, high blood pressure, diabetes and heart conditions, particularly AF. It’s a perfect storm with all those risk factors, which can unfortunately result in stroke at a relatively young age.”
The longer people have AF, the more the heart gets used to it and the worse it becomes. “Usually when AF starts it’s intermittent, what we call paroxysmal atrial fibrillation, and then over time it becomes more dominant until it becomes persistent atrial fibrillation all the time. And once that happens it’s very difficult to reverse,” Lowe says.
The aim is to break that spiral by getting people to spend as much time as possible in a normal rhythm. “The good news is it’s not too late. If you present with atrial fibrillation and you have sleep apnea, there is good evidence that treating the sleep apnea will help prevent further attacks of AF,” says Lowe. It may not even mean going on a Cpap machine; losing four to five kilos can have a significant impact on your heart rhythm issue.
“Often adopting these lifestyle modifications can lead to a significant improvement in the patient’s symptoms and can lead to a better outcome from interventional treatments for patients with atrial fibrillation such as catheter ablation,” says Professor Rinaldi.
“We think that 80-90 per cent of strokes could be preventable because of different risk factors that we understand like AF, high blood pressure and diabetes and lifestyle,” says Dr Richard Francis.
Lee, a teaching assistant, has co-founded SOS Survivors of Stroke (sos-survivorsofstroke.co.uk), to raise stroke awareness and offer support to others affected by stroke. “I’m lucky,” he says. “I have recovered well in comparison to some people who are bed-bound at my age or can never work again. But sharing my experiences and learning from others has been very valuable.”
What are the key risk factors for a stroke?
High blood pressure
High blood pressure plays a part in about half of all strokes. It can lead to blood clots in the brain, and can damage the tiny blood vessels deep inside the brain. It can also make a stroke due to bleeding in the brain more likely. A normal blood pressure range is up to 130 mm Hg, depending on the state of your health and whether you have other chronic health conditions.
Atrial fibrillation (AF)
AF is one of the most common forms of abnormal heart rhythm (arrhythmia) and a major cause of stroke. It is a heart condition that causes an irregular and often abnormally fast heart rate. AF happens when the electrical impulses in your top two chambers (the atria) that trigger muscle contractions of the heart fire chaotically when they should be steady and regular, causing them to quiver or twitch (fibrillation). If this happens you might feel an irregular and sometimes fast heartbeat or pulse.
“But many people don’t have any symptoms,” says Francis, “or very fleeting symptoms. So if you suspect anything, talk to your GP who can do more extensive testing including wearing a heart monitor for a few days to see if there’s any intermittent AF.”
Atrial fibrillation might come and go (paroxysmal atrial fibrillation), but sometimes it doesn’t go away at all. It’s not life-threatening, but it’s considered serious because it could create blood clots in the heart that may lead to a stroke. There is currently no cure for AF and the way it is treated is individualised to the patient’s needs. In the past, this meant through tablets including beta blockers or Amiodarone to control heart rate and rhythm (although they are not without side effects).
Today it is more likely to involve 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.
High cholesterol
Excess cholesterol enters your bloodstream and can cause a build-up of fatty deposits in your arteries, which can become narrow and stiff. This is a process called atherosclerosis. The damage to the artery wall can lead to a clot forming, which may travel to the brain and cause a stroke.
Diabetes
According to the Stroke Association, people with untreated diabetes accumulate too much glucose in their blood and their cells don’t receive enough energy. Over time, excessive blood glucose can result in increased fatty deposits or clots in blood vessels. These clots can narrow or block blood vessels in the brain or neck, cutting off the blood supply, stopping oxygen from getting to the brain and causing a stroke.
Age and gender
Age and gender are considered non-modifiable risks. “Age is unfortunately one of the biggest risk factors,” says Dr Francis. But lifestyle habits play a role in the rise of AF among the middle-aged.
Family history
A parental history of stroke may lead to an increased risk of stroke events.
Smoking/drinking too much alcohol/being overweight
When someone is sedentary and overweight, their heart is being put under stresses because of working harder to maintain a body that is heavier than it should be. This presents a huge physical strain for the heart that can result in AF.
Lack of exercise
A lack of fitness raises the risk of atrial fibrillation. But the good news is middle-aged adults who keep fit are significantly less likely to develop AF or suffer a stroke.
Researchers from the National Yang Ming Chiao Tung University in Taiwan tracked 15,450 people, none of whom had AF at the start of the study, assessing their fitness over a decade. Participants were aged 55 on average and were asked to complete a gruelling test on a treadmill to determine how fit they were. They were then followed up for a decade.
The study found that the fittest group were 8 per cent less likely to develop AF and 12 per cent less likely to have a stroke within the decade, compared with the middle group. They were also 14 per cent less likely to suffer major adverse cardiovascular problems, including heart attacks and early death, within that decade.
Stroke prevention advice
Check your pulse to see if you have atrial fibrillation
“You can use your two fingers on your pulse to check if your heart rhythm is regular or not,” says Richard Francis of the Stroke Association. An irregular pulse is a key sign, so contact your GP for further tests.
Oxygen levels
You can also check your oxygen levels overnight by wearing a pulse oximeter on your finger (blood containing lots of oxygen absorbs more infrared light). You can get one that links with your smartphone.
Lifestyle changes
Cut down on stimulants including alcohol (coffee/tea are OK). Alcohol is among the biggest stressors for AF. Just one small glass of wine a day, a single shot of spirits or a small bottle of beer is enough to raise the risk of AF by 16 per cent compared with non-drinkers, according to a 14-year study published in the European Heart Journal.
Use your smartwatch
Consider your smartwatch as a portable ECG on your wrist. Devices such as the Apple Watch or Fitbit can be set to flag up any abnormalities with your heart rate, which can then be analysed retrospectively for signs of AF.
“One huge growth area has been ECG monitoring’ says Dr Lowe. “Patients can now buy tiny ECG recording devices that you press with two fingers on a metal pad for 30 seconds. It downloads the ECG and it’s sent to your GP in PDF format, and it will give you a diagnosis - atrial fibrillation or a normal rhythm.”
It’s about empowering the patient to be able to make that diagnosis, says Professor Rinaldi. “Especially in terms of wearables which have come into the clinical decision-making process.”
Get active
Any form of cardiovascular exercise is good. Shih-Hsien Sung, professor of medicine at the National Yang Ming Chiao Tung University in Taipei and lead author of the university’s AF and stroke study, said: “Regular physical activity may help to reduce inflammation and improve the function of the heart, which may help to prevent the development of atrial fibrillation. "
Eat healthily
Follow a Mediterranean diet and cut down on salt. Weight loss in overweight people with AF slows progression and in some cases reverses the condition.
What causes stroke?
A stroke occurs when a blood vessel that supplies blood and oxygen to your brain becomes blocked or ruptures. This results in a lack of oxygen which causes your brain cells to become damaged or die.
A stroke can affect you in different ways, depending on which part of the brain hasn’t received the blood supply. It can affect your speech, as well as the way you think and move.
If you think you or anyone else may be having a stroke, call an ambulance immediately.
What are the different types of stroke?
Ischaemic strokes happen when an artery supplying blood to your brain is blocked by a blood clot.
Haemorrhagic strokes happen when a blood vessel ruptures (or bursts), causing a bleed in the brain. This means less blood gets to the surrounding brain cells, causing them to die.
Mini-strokes, or transient ischaemic attacks (TIAs), happen when there’s an interruption in blood flow to part of the brain for a short time, causing symptoms such as temporary speech loss. TIAs usually resolve after a few seconds or minutes.
Anticoagulation (medication to thin the blood) is a key factor in stroke risk reduction in the setting of atrial fibrillation. “The mainstay of treatment for patients at risk of stroke or who have had a stroke due to atrial fibrillation is the use of medicines to anticoagulate the patient,” says Professor Rinaldi.
“Previously that would have been with medicines such as Warfarin which require regular blood tests to monitor their effect, however we now have direct oral anticoagulants which have replaced Warfarin for the treatment of stroke risk in the majority of patients.”