No 'Fibs': Current Evidence About Atrial Fibrillation
It's easy to say the simple abbreviation for atrial fibrillation, afib or AF, but the topic is actually one of the more complex conditions in heart health. Afib is a type of heart arrhythmia or irregular heartbeat that affects more than 6 million people globally. Symptoms include fatigue, chest discomfort, exercise intolerance, shortness of breath, lightheadedness, and heart palpitations described as rapid, fluttering, or pounding.
Afib risk factors
"Family history is a factor, but afib is largely an age-related condition," says Hugh Calkins, M.D., director of the cardiac arrhythmia service and professor of medicine at Johns Hopkins Medicine, in a telephone interview. A recognized expert on the condition, he's published more than 600 manuscripts and book chapters on heart arrhythmias including afib.
He calls afib a condition versus a disease and says it's generally rare before age 50, but by age 80, one in 10 people has it. It is also relatively uncommon in African-Americans, but it is closely linked to body weight, as well as body mass and height.
"The heavier you get, or the taller you are, the more likely you are to develop afib," says Dr. Calkins. " Afib is common in horses, but very rare in mice."
Related research presented at EuroPrevent 2017 found that "big" women are three times more likely to develop afib than small women. The Swedish study followed 1.5 million women for more than 30 years. It seems big people with "the highest body surface area" also have larger atriums, which increases the risk of atrial fibrillation, the authors wrote.
Sleep apnea can raise risk for afib — nearly one-third of all afib patients have sleep apnea, Dr. Calkins says. Patients can get help from a sleep specialist, and both conditions can be treated simultaneously.
Alcohol, stress, and afib
Large amounts of alcohol also increase afib risk. "New Year's Day sees more emergency room admissions for afib than most other days," says Dr. Calkins.
"Honestly, the main finding is that there is no relationship between alcohol consumption and atrial fibrillation unless it is heavy drinking," concurs cardiologist Parveen Garg, M.D., of Keck Medicine of USC, who also talked to HealthCentral in a telephone interview. "After looking at all the studies, light and moderate drinking don't appear to have a relationship to afib."
One relevant study of more than 47,000 Norwegian participants found up to seven drinks a week did not increase afib risk, but definitely did at 14 drinks per week. The results were reported in the October 2017 issue of the Journal of the American Heart Association.
Finally, the stress animal is a major contributor to afib risk. "Using yoga, meditation, and mindfulness training can help decrease stress," Dr. Calkins says. "You can't change your family history or your ethnicity, but you can modify your weight and stress levels."
Work can also contribute to stress and afib. In 2017, a European Heart Journal study reported that people working 55 hours or were nearly 40 percent more likely to develop afib during the next decade.
Why is afib dangerous?
Afib puts us at a five times higher risk of stroke since the condition can cause blood clots. It also increases the risk of heart failure. Treatments include anticoagulants or blood thinners, medications to control a fast heart, such as beta blockers, and antiarrhythmic medications. Among these treatments, anticoagulants used in high-risk stroke patients are most important since they've been shown to dramatically reduce the risk of a stroke and also improve survival.
Additionally, a 2017 study from the European Heart Journal reported that blood-thinning drugs are associated with a significant reduction in dementia risk. A 2016 study in European Cardiology corroborates that finding.
In addition to medications, procedures also play a role in the treatment of patients with atrial fibrillation. These procedures including cardioversion or shocking the heart back to normal rhythm, catheter ablation, which is a nonsurgical approach to eliminating atrial fibrillation, and surgical ablation, a surgical approach to eliminating it.
A 2014 study Dr. Calkins co-authored in the European Heart Journal noted that "considerable evidence available from several prospective randomized trials shows catheter ablation of afib is superior to antiarrhythmic drug therapy in controlling afib and that afib ablation improves quality of life substantially."
"When considering treatment of atrial fibrillation, the number one priority is to determine if a given patient has an elevated stroke risk that warrants treatment with an anticoagulant,” says Dr. Calkins.
Additionally, a growing body of evidence names afib as a risk for cognitive decline and dementia, yet another reason to manage this potentially dangerous condition, says a 2016 study in European Cardiology.
Depression invites afib
A study, presented at the American Heart Association Epidemiology and Prevention | Lifestyle and Cardiometabolic Health 2018 Scientific Sessions meeting, for which Dr. Garg was lead author, found that depression symptoms are associated with increased risk of afib.
"Mental health is an emerging concern, with many implications for physical well-being," he says. "The connection between brain and heart is much more appreciated in medicine now. It's suggested that depression may increase certain levels of hormones in our body that in turn increase risk of developing arrhythmia."
His study, with 6,644 participants, determined the relationship of both depressive symptoms and antidepressant use with incident afib in a multi-ethnic cohort. "Understanding and identifying risk factors is going to be more of a priority as the population ages," says Dr. Garg. "That may also help us target patients at risk for developing the condition. Afib is an emerging problem in America and in the developing world, and as we live longer, the burden of afib is exploding."
About the study he says, "We need to confirm our findings in other cohorts or populations — including larger populations — and in different ethnicities."
For even more helpful information about afib, visit StopAFib.org, from founder and CEO Mellanie True Hills, who says she is now cured of the condition. Dr. Calkins is a member of her advisory board.
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