Dr. John Day, Cardiologist

The Top 10 Atrial Fibrillation Triggers

A few years back, my good friend, Mellanie True Hills, the founder of the StopAF.org website, teamed up with researchers from the University of California at San Francisco in an effort to better understand atrial fibrillation triggers. What they found in their investigation was that people who are healthier usually have definitive triggers, while people who are less healthy might not even require a trigger to push their heart out of rhythm. They also found that while just about everyone has different triggers, some triggers are far more common than others.

There’s an important distinction to make here between causes and triggers. It’s important to understand both, but the long-term factors that put people at greater risk of AFib, also known as substrate causes (like bad genetics, being overweight, high blood pressure, etc.), aren’t always the same things that prompt a specific incident of AFib. Here, a wildfire analogy might be helpful: Any spark can trigger a single blaze, but the chances of having lots of fires in a season are greatly increased by conditions that accumulate over time, including drought, insect infestation and the growth of underbrush.

1. Alcohol

The top three atrial fibrillation triggers according to Mellanie True Hills study? Alcohol, caffeine and exercise—in that order. While all of these factors may be part of the combination of causes that pushes people toward AFib, it would be very rare for any of these factors alone to be the sole cause. But once someone is at that precipice, alcohol, caffeine and exercise can be powerful inciting events that can send their heart into chaos.And that shouldn’t come as a big surprise, particularly when it comes to that first trigger; any emergency room doctor can share many stories of high school or college students who have presented with AFib after binge drinking.

Alcohol use doesn’t just increase the risk of AFib. It also increases the risk of countless other diseases, including cancer. And while there are some studies that have demonstrated that a small amount of alcohol can offer some health benefits, when it comes to all-cause mortality those benefits are outweighed by the increased risk of other health-related harms, according to a 2018 study in the prestigious British medical journal The Lancet, that pulled no punches. “The conclusions of the study are clear and unambiguous: alcohol is a colossal global health issue,” the authors wrote, adding that there was strong support for a guideline published by the chief medical officer of the United Kingdom, who found there is “no safe level of alcohol consumption.

2. Caffeine

Caffeine is a powerful stimulant that can have a significant impact on our hearts. Fortunately, for most people with AFib, caffeine isn’t a problem. Indeed, studies have shown that the caffeine that comes from chocolate, coffee, and tea don’t trigger AFib for most people. However, for some people, like the 28% of the 1,298 people participating in Mellanie True Hills’ study, caffeine is indeed an important trigger for Afib attacks.

3. Exercise

Exercise is the most natural way in the world to shift our hearts into a higher gear, so it’s no shock that, if your heart is already prone to beating erratically, a quick burst of exercise could push it over the edge. In general though, it is extreme levels of exercise, exercising at levels beyond where you have trained, or exercising in a dehydrated or electrolyte depleted state in someone that is already prone to AFib attacks that trigger AFib episodes.

Most of my patients are shocked when they learn that people who run marathons, competitively cycle, or do Ironman triathlons are five times more likely to develop atrial fibrillation. What is particularly perplexing, however, is that studies have not tended to show higher rates of arrhythmias in athletes who participate in other strenuous forms of exercise, such as boxing, wrestling and weight-lifting. There is something particular about endurance sports that increases the risk of AFib. (One exception to this may be football. Among former NFL athletes, the risk of AFib is six times higher, although this may be due to the use of performance-enhancing substances or the weight these athletes put on to compete at a professional level.)

Also, it bears noting that while aggressively competing in endurance sports might put you at a greater risk of AFib, participation in these activities certainly does not guarantee you’ll get AFib. It is reassuring to note that recreational participation in endurance sports, even if it is a marathon or triathlon, doesn’t seem to put you at risk of AFib.

4. Sleep

After alcohol, caffeine, and exercise, the second tier of AFib triggers include lack of sleep, dehydration, large meals, and stress and anxiety.  The impact of poor sleep on AFib has been well documented. Even small interruptions of sleep quality and duration can increase the risk of atrial fibrillation by 18 percent, and people who experience insomnia are 30 to 40 percent more likely to develop atrial fibrillation. People who do not reach deep levels of sleep—the sort of sleep that is key to recovery—have an 18 percent increased risk of atrial fibrillation, and it worsens each time they wake up at night. It’s even worse for people with sleep disorders such as sleep apnea; they have a 200 to 400 percent increased risk of AFib over individuals without a sleep breathing disorder. And the problem is compounded once AFib actually develops; the presence of an abnormal rhythm can increase the risk of poor sleep quality, or short sleep, by three to four times. It’s a vicious cycle.

5. Dehydration/Electrolyte Imbalance

Even simple incidences of dehydration can tip the balance of the electrically charged ions potassium, sodium, calcium and magnesium, which play critical roles in ensuring your body holds onto enough water to function and help direct the electrical impulses that keep your heart beating. That, of course, makes levels of electrolytes that are too high or too low a potential danger—especially to people who might already be prone to atrial fibrillation for other reasons. One study from researchers in The Netherlands showed that low levels of potassium could quadruple the chances of AFib in some individuals. Those experiencing magnesium deficiency are also at considerable risk.

6. Large Meals/Specific Food Triggers

Why would food a large meal or a specific food be a trigger of an AFib attack? Perhaps because gastrointestinal problems, including stretching your stomach from a large meal, are known to stimulate the vagus nerve, which connects your gut, brain and heart. We don’t understand this connection in depth, but our research has shown that gastrointestinal distress, like from a large meal, are associated with atrial fibrillation. Also, when those gastrointestinal issues have resolved, the AFib usually settles down as well.

We have also had many patients report to us over the years that sugar, fast foods, foods with caffeine, processed foods, fried foods, or really spicy foods have also been atrial fibrillation triggers—not just contributors to the rising risk of getting AFib in the first place. Once again, all of these triggers probably had something to do with vagus nerve stimulation or glucose fluctuations. Surprisingly, in 30 years of seeing AFib patients, I have yet to hear a patient report to me that broccoli or kale triggered an AFib attack.

7. Stress/Anxiety

9. Cold Beverages and Foods

Another culprit that might be a potent trigger: very cold foods. That’s what a research team from California learned when they reviewed the case of a young adult man who drank one of those sugary “slushed ice” drinks, the type of which you commonly find at gas station convenience stores. Just about everyone who has tried one of these drinks knows the sensation of “brain freeze,” an intense, rapid-onset headache also known as sphenopalatine ganglioneuralgia, that is caused by sudden temperature changes to the carotid artery and anterior cerebral artery, which are located near the back of the throat, and which feed blood to the brain. The man immediately began to suffer from both atrial fibrillation and brain freeze at the same time.

Researchers have theorized that the vagus nerve may be similarly stimulated. This doesn’t mean we need to avoid cold foods; we just need to be mindful of how we consume them. When it comes to smoothies, slow and steady wins the race.

10. Not Exercising

Regular daily exercise in general isn’t risky at all—in fact, it’s exceptionally protective against AFib and just about every other chronic medical problem. To put things into perspective, for every thousand patients we see with atrial fibrillation, perhaps one may be at risk for atrial fibrillation due to overexercising. The biggest problem, by far, is that most patients aren’t exercising enough. There is far greater risk to not exercising enough than to exercising too much. People who live sedentary lifestyles are at significant risk of AFib, not to mention all of the other health consequences of not getting enough exercise.

Next Steps if You Have AFib Triggers

If you have clear and identifiable triggers, and can easily avoid them, then that is your best option to prevent AFib attacks. But please remember that triggers alone probably won’t incite an AFib event unless you are already prone to AFib attacks from things like bad genetics, carrying too much weight, high blood pressure, etc. And your best best to beat AFib is to not only avoid the triggers but to also address the underlying causes which put your at risk for AFib in the first place.

As you probably liked this article to get this far, please be sure to sign up for my monthly AFib newsletter and pick up a copy of the best selling book on the topic, The Atrial Fibrillation Cure. The Atrial Fibrillation Cure represents everything we have learned about atrial fibrillation over the last 30 years.

About the Photo

This is a picture of the beautiful Desolation Lake in the Wasatch Mountains at approximately 9,000 feet above sea level near my home. At least a couple times a week in the summer and fall, I’ll hike up to the lake. In the winter and spring, I’ll backcountry ski in this area.