Is Caffeine Safe, Protective For Patients With AFib, Arrhythmias?
Some caffeinated beverages ─ such as coffee and tea ─ may be safe and may reduce the frequency of arrhythmias, according to a state-of-the-art-review published April 16 in JACC: Clinical Electrophysiology.
Aleksandr Voskoboinik, MBBS, et al., analyzed multiple population-based studies to determine an association between caffeine intake and its effects on atrial and ventricular arrhythmias. The studies consistently showed a decrease in atrial fibrillation (AFib) with an increase in caffeine ingestion, with one meta-analysis of 228,465 participants showing AFib frequency decreasing by 6 percent in regular coffee drinkers, and a further analysis of 115,993 patients showing a 13 percent risk reduction.
The authors found that caffeine “does not appear to increase the likelihood of ventricular arrhythmia.” In addition, caffeine doses up to 500 mg daily (approximately six cups of coffee) did not increase the severity or rate of ventricular arrhythmias. A randomized study of 103 post-MI patients who received an average of 353 mg/day resulted in improved heart rate and no significant arrhythmias. Only two studies showed an increased risk for ventricular arrhythmias, in which patients ingested at least 10 cups and nine cups per day, respectively. According to the authors, energy drinks should be avoided by patients with pre-existing heart conditions. Three quarters of patients with pre-existing heart conditions who consumed two or more energy drinks per day reported palpitations within 24 hours.
Both large population studies and randomized control trials suggest caffeine intake of up to 300 mg/day may be safe for arrhythmic patients. However, there may be individual differences in susceptibility to the effects of caffeine on the factors which trigger arrhythmias in some, and up to 25 percent of patients report coffee as an AFib trigger. Patients with a clear temporal association between coffee intake and documented AFib episodes should accordingly be counseled to abstain. Future research looking at the relationship between heart rhythm patients and the impact of caffeine abstinence may be useful to further clarify this topic.
“Caffeinated beverages such as coffee and tea may have long term anti-arrhythmic properties mediated by antioxidant effects and antagonism of adenosine,” the authors conclude. “In numerous population-based studies, patients who regularly consume coffee and tea at moderate levels have a lower lifetime risk of developing heart rhythm problems and possibly improved survival.”
Keywords: Coffee, Caffeine, Anti-Arrhythmia Agents, Atrial Fibrillation, Energy Drinks, Antioxidants, Heart Rate, Adenosine, Risk, Heart Atria, Tea, Risk Reduction Behavior, Electrophysiology
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