Results of a new study suggest that patients with paroxysmal atrial fibrillation (PAF) should avoid consuming alcohol to reduce the risk of AF episodes, but the exact link between alcohol and arrhythmias is still poorly understood [1].
Dr Gregory Marcus (University of California, San Francisco) and colleagues previously reported trial results showing that daily consumption of alcohol by patients younger than 60 increases the risk of atrial fibrillation and flutter and that the risk of atrial flutter especially increases with greater alcohol consumption. "It looked like that might be related to a shorter atrial refractory period, which theoretically could have some causal mechanisms related to atrial fibrillation, but there's been very little research on understanding those mechanisms," Marcus toldheartwire .
"There's generally a perception out there that alcohol is good for your heart, but it looks like there's something going on that's probably important and could be detrimental electrically, so that's pertinent to everyone who drinks alcohol. Second, if we could really understand how alcohol triggers atrial fibrillation, we might learn something important about atrial fibrillation itself." He also suggested that this question is "ripe for a randomized study," comparing arrhythmia episodes of patients consuming alcohol with those not consuming alcohol.
Marcus and medical student Mala Mandyman (University of California, San Francisco) are the lead authors of a study, scheduled for the August 1, 2012 issue of the American Journal of Cardiology, comparing the self-reported frequency of PAF episodes in patients with previously documented PAF with the frequency of episodes of patients with other types of supraventricular tachycardia (SVT).
At a single center, 223 patients with a documented arrhythmia (133 with PAF and 90 with SVT) completed a survey detailing their alcohol-consumption pattern and arrhythmia episodes. Episodes were considered triggered by vagal activation if the subject's episodes usually began while the patient was resting or eating or if the symptoms terminated with exercise. If the episode was triggered after the patient was exercising, stressed, or consuming caffeine, the episode was considered triggered by sympathetic activation.
After multivariable adjustment, the patients with PAF had a 4.42 greater odds of reporting alcohol consumption (p=0.014) and a 2.02 greater odds (95% CI 1.02–4.00) of reporting vagal activity (p=0.044) as the arrhythmia trigger compared with patients with SVT. Younger age (odds ratio 0.68, p=0.022) and a family history of AF (OR 5.73, p=0.028) each were independently associated with vagal activation of episodes. Patients with PAF and alcohol triggers were more likely to report vagal triggers of arrhythmias (OR 10.32, p=0.045).
In patients with PAF, beer was the type of alcohol most commonly cited as a trigger (odds ratio 4.49, p=0.011), although the authors note that the questionnaire only asked what type of alcohol the subject drank the most, rather than what they were drinking before each episode. This association may be due to beer drinkers generally drinking more alcohol overall compared with those who prefer wine or spirits, but this association persisted after adjustment for average consumption and bingeing, Mandyam et al point out.
"It does appear that certain patients are more or less prone to alcohol triggering their symptoms. I don't think we know--there are conflicting data from large epidemiological studies--if alcohol actually causes atrial fibrillation," Marcus said. "So there are insufficient data to give a strong recommendation, [but] certainly in people in whom alcohol has triggered atrial fibrillation, I recommend abstinence [in the future]." With everyone else, Marcus advises moderation.
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