If you have a rapid, racing heartbeat and feelings of weakness, you may have atrial fibrillation. The most common arrhythmia originating in the atria, the upper chambers of the heart, atrial fibrillation has many causes. Abnormal electrical impulses in the atria cause the upper chamber to contact rapidly and irregularly. Atrial fibrillation affects between 5 to 10 percent of people over age 65, according to a March 2005 article in the "American Journal of Clinical Nutrition" written by researchers from Wageningen University Division of Human Nutrition. Caffeine has been implicated as a potential cause of atrial fibrillation.
Definition
The atria contract as many as 300 to 600 times a minute in atrial fibrillation, according to the Cleveland Clinic. Normally, the atria contract just once for every contraction of the ventricles, the lower chambers that pump blood out to the rest of the body. If you have atrial fibrillation, you may feel like your heart is fluttering, and you may have shortness of breath or chest pain.
Caffeine Actions
Caffeine is a central nervous system stimulant that can speed up your heart rate and cause feelings of anxiety, jitteriness and restless, which can be similar to the side effects of atrial fibrillation. Many substances contain caffeine, including coffee, tea, colas and energy drinks.
Causes
Various types of heart disease most often cause atrial fibrillation, including coronary artery disease, high blood pressure, heart failure and pericarditis, inflammation around the heart. In around 10 percent of cases, no heart disease is found to account for atrial fibrillation. Excessive caffeine intake may contribute to these cases, the Cleveland Clinic states. Drinking five cups of coffee per day raises systolic blood pressure by 2.4 mm/Hg, which could contribute to development of atrial fibrillation, according to researchers from Wageningen University. A rapid heartbeat can further damage an already damaged heart, Brown University Health Education reports, increasing the risk of atrial fibrillation.
Studies
Several studies have shown no connection between caffeine intake and atrial fibrillation. Danish researchers from the Aarhus University Hospital found no connection between caffeine intake and atrial fibrillation. The study examined data from 47,949 people with an average age of 56 in the Danish Diet, Cancer and Health Study. An animal study conducted by the University of Oklahoma Health Sciences Center and reported in the October 2006 "Journal of Electrocardiology" found that, contrary to popular belief, intravenous caffeine intake decreased rather than increased the chance of developing atrial fibrillation, at least in dogs. Further human studies are required to determine the effects of caffeine.
References
- "American Journal of Clinical Nutrition"; Caffeine and Risk of Atrial Fibrillation or Flutter: The Danish Diet, Cancer, and Health Study; L. Frost, et al.; March 2005
- Cleveland Clinic: What Is Atrial Fibrillation? September 2010
- "Journal of Electrocardiology"; The Effects of Caffeine on the Inducibility of Atrial Fibrillation; A. Rashid, et al.; October 2006
- "American Journal of Clinical Nutrition"; Caffeine and Arrhythmia; Martijn B. Katan, et al.; March 2005
- Brown University Health System: Caffeine
