If you, or someone you know, has recently been diagnosed with atrial fibrillation, you’ve probably begun to explore what this means for you and what comes next. Atrial fibrillation (AFib) is a common heart rhythm disorder where the heart’s upper chambers (the atria) beat irregularly and too fast. This prevents the heart from pumping blood efficiently around the body and can trigger symptoms such as palpitations, breathlessness and fatigue.
When it comes to treating AFib, cardiologists typically look at several key areas:
- Medicines to control your heart’s rate and rhythm, or to reduce the risk of blood clots and stroke
- Medical procedures such as cardioversion (electrical energy to restore normal rhythm) or cardiac ablation (targeting the tissue that’s causing the faulty electrical signals in your heart)
- Lifestyle modifications, including things like managing stress, limiting alcohol intake and addressing your weight.
But that last point raises an important question. If “addressing your weight” can help you manage your AFib, could it actually reverse the condition entirely?
Is it possible to reduce your symptoms, or even stop the irregular rhythm itself, just by reaching a healthier weight?
What counts as too much weight?
When doctors talk about weight and heart health, they’ll often refer to your Body Mass Index (BMI). A BMI of less than 25 is generally considered a healthy weight. Above 25 is technically overweight. And a BMI of 30 or higher is usually classified as obese.
Doctors do this because they know that, statistically, obesity significantly raises the risk of developing conditions like AFib: a person with a BMI of 30+ is in fact twice as likely to have the condition. This is a particular cause for concern here in Ireland, since more than half of us are classified as overweight or obese. That’s one of the highest rates in the EU.
BMI alone isn’t a flawless way to judge the “healthiness” of your weight. As the HSE points out, “if you have a lot of muscle, you may have a high BMI despite having low body fat. In this case, your waist circumference (the distance around your waist) may be a better guide.” But as a general guide, it can be a useful indicator.
Calculate Your BMI
1) Measure your weight in kilos and your height in metres
2) Multiply your height by itself (this gives you your “height squared”)
3) Divide your weight by your height squared. If maths isn’t your strong suit, the Cork-based public health body Safefood has a useful BMI Calculator on its website.
How does weight affect the heart?
Excess weight puts more physical and chemical strain on your cardiovascular system. You can see this very clearly in some of the research that has emerged in recent years. One of the best-known examples – the Framingham Heart Study in the US – found that the occurrence of AFib rose by 4-5% for every single-unit increase in BMI. This is a significant upward trend. But how exactly does it do that?
Structural changes
Carrying extra weight forces the heart to work harder than normal. But it can cause physical damage to the heart’s structure too. Excess fat increases the volume of the left atrium, putting the heart under greater pressure. This also creates more room for abnormal electrical patterns to develop, like the erratic patterns we typically see in AFib.
Electrical disruption
Fat doesn’t just sit harmlessly around the heart. High volumes of pericardial fat (fat that’s deposited around the heart) are inflammatory and can actively change how the heart works. Studies have found these fat cells can directly impact the electrical properties and ion channels in the heart muscle cells of the left atrium.
Artery blockages
Over time, excess fat around the body begins to build up in the arteries. This can restrict or even block the passage of blood through your body, preventing the ventricles from filling properly between heartbeats. This in turn raises the risk of problems like coronary artery disease, stroke – and of course rhythm issues like AFib.
What other problems does weight cause?
Obesity can create a kind of domino effect in the body, triggering other health problems that, independently, raise your risk of developing AFib – or of making your AFib worse if you already have it. For instance, being overweight makes you more likely to develop problems like:
- high blood pressure
- sleep apnoea (where breathing repeatedly stops and starts during sleep)
- coronary artery disease (where plaque builds up in the arteries)
- diabetes
And each of these conditions, in turn, raise your risk of developing atrial fibrillation: a classic vicious circle.
Can losing weight actually reverse AFib?
The good news is that losing excess weight can have a powerful effect on AFib (more on which below). But can it actually reverse or stop the condition? It’s worth explaining what we mean by reversal.
When cardiologists talk about “reversing” AFib, they mean putting a stop to the irregular rhythms you’re experiencing, returning your heart to a normal rhythm, and reducing or eliminating those unpleasant symptoms. But there’s an undoing element here, too. The burden of AFib (meaning the amount of time your heart spends in the chaotic rhythm) can progress over time, from occasional bouts of atrial fibrillation to much more regular episodes. The classic stages of AFib are:
Paroxysmal AFib – where the irregular rhythm occurs temporarily, perhaps from hours to a day or two, before disappearing
Persistent AFib – where the irregular rhythm remains for a longer period of time, perhaps a week or more
Permanent or Long–standing Persistent AFib – where the irregular rhythm is present all the time
So, for some patients, “reversing AFib” could mean shifting from persistent AFib (longer-lasting runs) to paroxysmal AFib (occasional episodes). In an ideal situation, it could mean stopping the irregular rhythms entirely and bringing the heart back into a normal rhythm for the long term.
What does the science say about obesity, weight loss and AFib?
Clinical guidelines from organisations such as the European Society of Cardiology (ESC) and the Heart Rhythm Society increasingly emphasise the importance of risk-factor management, including weight control, in the long-term management of atrial fibrillation.
The really encouraging news from recent research is that loss of excess weight does appear to have the potential to reverse or stop atrial fibrillation.
The LEGACY evidence – can you reverse Atrial fibrillation?
This Australian study was published in the Journal of the American College of Cardiology in 2015. Researchers at the University of Adelaide followed 355 AFib patients with a BMI of 27 or higher as they underwent a weight loss programme, in some cases for up to four years.
They found that patients who shed at least 10% of their body weight were six times less likely to have the irregular heartbeat again. Even more encouragingly, nearly half (46%) of those patients were still completely free of AFib after five years, without needing any rhythm-control medications or surgery.
The REVERSE-AF follow-up
This 2018 study did a retrospective analysis of the LEGACY findings, but took a slightly different angle on the data. Their results found a striking relationship between weight loss and the progression of AFib.
“The study showed that if obese people lose more than 10% of their weight and subsequent management of other risks to their lifestyle, they can reverse the progression of the disease,” said lead author Melissa Middeldorp.
“People who lost weight experienced fewer symptoms, required less treatment and had better outcomes. Those who previously had sustained symptoms experienced only intermittent symptoms or indeed stopped experiencing [AFib] entirely.”
A note of caution
The evidence around weight and AFib isn’t entirely one way. For example, one recent trial in Oxford found that for older patients (aged 60-85) with persistent AFib, weight loss on its own didn’t improve heart rhythm symptoms or reduce the need for further treatment.
Other research has suggested that, while excess weight increases the risk of developing atrial fibrillation, people who already have the condition sometimes have better long-term survival rates compared with AFib patients who have a healthy BMI.
This even has a name: the Obesity Paradox.
But does that mean we can safely ignore the standard advice around weight loss and heart health?
Well, no. As any doctor will tell you, obesity is a health risk on many different levels. And getting to a healthy weight is one of the best non-clinical things you can do to protect your heart from cardiac problems and rhythm complications.
What are the most effective ways to lose weight for AFib?
So if you wanted to manage your AFib by getting to a healthier bodyweight, what are the best ways to go about it? There are three main approaches to take:
Lifestyle
The obvious one. Introducing more movement into your day, refocusing your diet on healthier foods and tracking progress to keep up motivation are the tried-and-tested natural ways to shed weight.
The Irish Heart Foundation has some great resources to help with this: see their Practical advice for real-life health and the tips and tools sections to explore, further down the page.
But, as we all know, losing weight naturally can be very hard work, not least because our bodies react against it by slowing down our metabolism, increasing hunger hormones and decreasing the feeling of fullness. That’s why doctors often recommend doing it with support from a weight-loss group or programme.
Weight-loss drugs
Weight-loss injections like Ozempic and Wegovy have been making plenty of headlines recently. Ozempic is the brand name for an active ingredient called semaglutide, a “glucagon-like peptide-1” (GLP-1) that mimics one of the body’s appetite-suppressing hormones.
A substance called tirzepatide, branded as Mounjaro, works in a similar way. The jury may be out on whether weight-loss injections are beneficial over the long term, but recent studies have suggested they may have a powerful impact in the context of AFib.
One recent meta-analysis found that semaglutide was associated with a 30% reduction in AFib occurrence compared to control medications. Another study for the European Heart Journal found the odds of developing new-onset AFib were more than 40% lower in patients using semaglutide.
Surgery
When other weight-loss approaches haven’t worked or aren’t appropriate for treatment, doctors sometimes recommend surgery to reduce obesity.
Bariatric surgery involves reducing the size of the stomach or bypassing a section of the bowel. Recent research has suggested it can be highly effective for people with AFib. One US study, led by Irish electrophysiologist Eoin Donnellan, examined 220 patients with a BMI of 40+ (morbid obesity). It found a remarkable reversal of AFib in 71% of patients who had a gastric bypass, 56% of patients who underwent sleeve gastrectomy and 50% of patients following gastric banding.
“Bariatric surgery is associated with significant reductions in weight, inflammatory markers, blood pressure, and [AFib] type, and the beneficial effects appear to be the greatest in those undergoing gastric bypass surgery,” the authors concluded. “This study further exemplifies the importance of weight loss and risk factor modification in AF management.”
Key takeaways
- Obesity significantly increases the risk of developing atrial fibrillation.
- Excess body fat can cause structural and electrical changes in the heart.
- Losing around 10% of body weight has been shown to reduce AFib burden in many patients.
- Weight management works best alongside medical treatments such as medication or ablation.
- Managing related conditions such as sleep apnoea, diabetes and high blood pressure is also important.
Let Heart Rhythm Cardiologist help
Living with atrial fibrillation, or getting that initial diagnosis from the doctor, can certainly feel daunting. But you don’t have to go through it on your own. There are more effective treatments and lifestyle tools available to us today than ever before.
If you’re concerned about your heart rhythm or would like to discuss how weight management could improve your AFib, we’re here to help.
Call the team or email us here to schedule a consultation with Dr Lyne.
Whatever your situation, we’re here to get you the support you need.
Frequently asked questions about weight and atrial fibrillation
Weight loss can reduce AFib symptoms and the frequency of episodes, and in some cases may help restore normal rhythm. However, it is not a guaranteed cure and many patients still require medication or procedures.
Research suggests losing around 10% of body weightcan significantly reduce AFib burden and improve rhythm outcomes.
Obesity can cause structural changes in the heart, increase inflammation, and raise the risk of related conditions such as high blood pressure and sleep apnoea, all of which can trigger AFib.
Yes. Studies suggest that maintaining a healthy weight can improve the success rate of catheter ablation and reduce the chance of AFib returning.
This article was medically reviewed by Dr Jonathan Lyne, Consultant Cardiologist and Electrophysiologist, who specialises in diagnosing and treating heart rhythm disorders, including atrial fibrillation.
