By Nicholas Tullo, MD
Atrial fibrillation (AF) is a common heart rhythm disturbance that affects millions of Americans. It is characterized by an irregular heartbeat that often causes rapid palpitations. A cup of coffee contains nearly 90-100 mg of caffeine, which can act as a central nervous system stimulant. From the very beginning, physicians have advised AF patients to avoid coffee and other caffeinated beverages for fear that these “stimulant” drinks might trigger or worsen the tendency towards having atrial fibrillation. Doctors have even gone as far as telling AF patients to not eat chocolate, because of the tiny amount of caffeine-like substances found in this otherwise enjoyable treat. However, recent evidence published in a state-of-the-art review[*] now suggest that coffee and tea appear to be safe and may actually reduce the frequency of arrhythmias in some patients, perhaps due to the well-known anti-oxidant benefits of these substances.
The report was published in the Journal of the American College of Cardiology, and reviewed multiple studies including one of over 228,000 participants that showed AF frequency decreased by 6% in regular coffee drinkers. In addition, other arrhythmias such as premature ventricular contractions (PVCs) were not affected by caffeine doses up to 500 mg (equivalent to 5-6 cups of coffee). One randomized study of 103 patients who had a heart attack and were consuming over 3 cups of coffee per day showed an improved heart rate and no significant arrhythmias. Only two studies showed an increase of ventricular arrhythmias, but that was in patients who drank more than 9-10 cups of coffee per day.
So-called “energy drinks” can contain large amounts of caffeine (up to 500 mg per serving). They can potentially cause problems with palpitations, especially if two or more of these are consumed on the same day.
To be truthful, some patients happen to be very sensitive to caffeine and do report that coffee or tea tends to trigger AF episodes. They can almost guarantee getting palpitations after drinking caffeine, and many AF episodes were triggered by a cup of regular coffee that was served by mistake (instead of decaf) at a local restaurant. Of course, those patients should be counseled to avoid any substance that clearly makes them feel poorly, including coffee.
In summary, a small number of patients may be extremely sensitive to caffeine and should avoid consuming anything that they know will have an adverse effect on them. However, in general patients with AF do not need to avoid moderate amounts of coffee, tea, or even chocolate if they enjoy them. There does not appear to be any harm in having a couple of cups per day, and many studies actually show evidence of benefit. So start brewing that java and drink up!
[*] Voskoboinik A, et al. JACC Clin Electrophysiol 2018;4:425-32.
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