How heart fat can lead to atrial fibrillation

Did you know that fat around your heart could play a big role in heart problems? Today, we are diving into how a special type of fat called epicardial adipose tissue (EAT) can affect your heart’s rhythm and why scientists are working hard to understand this better.

What is atrial fibrillation and why does it matter?

Atrial fibrillation (AF) is a condition where the heart beats in a fast and irregular way. It’s actually the most common problem with heart rhythm in adults, affecting about 60 million people around the world. When someone has AF, they might feel their heart racing, get tired easily, or even feel dizzy. More seriously, AF increases the risk of stroke and heart failure. This makes it a big concern for doctors and patients alike. Experts have found that certain things like getting older, having high blood pressure, diabetes, drinking a lot of alcohol, and especially being overweight can raise the risk of developing AF. In fact, obesity is known to be a strong risk factor for this irregular heart rhythm, as shown in large population studies (Larsson et al., 2014).

Meet epicardial adipose tissue: the heart’s own fat layer

Epicardial adipose tissue (EAT) is a layer of fat that sits right on top of your heart, without anything separating it from the heart muscle. At first, EAT actually helps protect the heart by acting as a cushion and giving the heart energy in the form of fatty acids. It even releases substances that help reduce inflammation in the heart. But as we get older or gain a lot of weight, this fat layer can change. It starts to lose its protective qualities and instead begins to cause trouble by releasing substances that can make the heart inflamed and less healthy (Zou et al., 2023).

How does EAT increase the risk of atrial fibrillation?

Scientists have learned that people with more EAT are more likely to develop AF. This is because the fat can send out signals that affect the heart muscle. Some of these signals, called cytokines, can cause inflammation and scarring (fibrosis) in the heart, which then makes it easier for the heart to beat in a disorganized way. Also, EAT can physically invade the heart muscle, making it harder for the electrical signals that control the heartbeat to travel smoothly. This creates the perfect environment for AF to start and continue.

Research using animal models like sheep and pigs, which have EAT similar to humans, has been key in understanding how this process works. For example, scientists have seen that when these animals are fed a high-fat diet, they develop more EAT and more heart rhythm problems, just like people do (Boixel et al., 2003).

How do scientists study EAT and AF?

Studying EAT in people can be tricky, because it’s hard to get samples of this fat while someone is alive. That’s why scientists use different models to understand the connection between EAT and AF. Animal models (like sheep or pigs) are helpful because their hearts are similar to ours. Scientists can also grow human heart and fat cells in the lab using special stem cells called iPSCs. These models help researchers see exactly how EAT affects the heart’s rhythm at the cellular level (Thorpe et al., 2023).

These lab-grown models are important for testing new medicines that might stop EAT from causing AF. However, there are still challenges, like making sure the lab-grown cells act just like real heart and fat cells.

What it means for patients

Understanding the relationship between EAT and AF is crucial because it could lead to new ways to prevent or treat AF, especially in people who are overweight. If doctors can find ways to keep EAT healthy or stop it from harming the heart, they could help many people avoid AF and its serious complications.

For those interested in how your own health information can help advance this kind of research, but also how to protect your privacy, check out this helpful overview on keeping your health data private with AI. And if you are curious about why your health information is so valuable for research and care, this SlothMD article explains what health data is and how health AI is changing medicine for the better.

The future: hope for new treatments

As scientists continue to develop better models, like more realistic lab-grown heart tissues (Liu et al., 2022), they will be able to find new drugs or therapies that can target the harmful effects of EAT. This means that in the future, people at risk for AF might have more options to keep their hearts healthy—thanks to research on this unique heart fat, advances in health AI, and the use of platforms like SlothMD to share health knowledge safely.