Atrial fibrillation, commonly called A-fib, is an irregular heart rhythm that originates in the atria or top chambers of the heart. The upper chambers beat out of rhythm with the bottom chambers, with the top chambers “quivering.”

Atrial fibrillation is the most common heart arrhythmia. It is more common in individuals of European descent than African Americans. More women than men have atrial fibrillation because of their longer life span. Your risk for atrial fibrillation increases with age.

Symptoms

• Heart palpitations, irregular heartbeat, fluttering or skipped beats
• Shortness of breath both at rest and with activities
• Dizziness
• Fatigue
• Weakness
• Chest discomfort

Some individuals will have no symptoms with atrial fibrillation and it is found incidentally on a routine exam.

Causes

Atrial fibrillation may be caused by various health or environmental issues, including:

• High blood pressure
• Heart failure
• Cardiomyopathy
• Coronary artery disease
• Heart valve disease
• Previous heart surgery
• Congenital heart disease
• Birth defects involving the heart
• Chronic lung disease such as COPD, asthma and emphysema
• Pulmonary embolism (blood clot in the lungs)
• Thyroid problems

Environmental issues that can cause atrial fibrillation include:

• Excessive caffeine consumption
• Excessive alcohol intake (including binge drinking)
• Stress

However, in some individuals, there is no known cause of their atrial fibrillation.

Treatments

Various treatments help with the symptoms of atrial fibrillation:

• Medications (antiarrhythmics) to help maintain a normal heart rhythm
• Cardioversion, or shock to the heart, to restore normal heart rhythm
• Ablation to target the source of the chaotic electrical impulses in the heart
• Maze procedure to create scar tissue in the upper chambers of the heart
• Permanently implanted devices such as pacemakers or loop recorders

Consequences

Atrial fibrillation increases stroke risk. An individual with atrial fibrillation is five times more likely to have a stroke than someone without it. When the heart does not squeeze properly, it allows blood to pool in the upper chambers of the heart, creating the opportunity for blood to clot. These blood clots can then move out of the heart and travel to the brain, blocking blood supply and causing a stoke.

Atrial fibrillation can also lead to heart failure when heart rates are uncontrolled. This is because the heart is not efficiently pumping blood to the lungs and body.

Preventing Stroke

Oral anticoagulation medication (“blood thinners”) increase the time it takes for blood to clot. While very effective, these medications can have side effects including gastrointestinal bleeding, brain bleeding, frequent falls and excessive bruising. For individuals for whom long-term use of blood thinners is problematic, there is an alternative.

In people with atrial fibrillation, more than 90% of stoke-causing clots come from the left atrial appendage. Devices to occlude this area have been developed. The device is placed in the left atrial appendage, a small area on the upper left chamber of the heart. The U.S. Food and Drug Administration has so far approved two such devices, Watchman (made by Boston Scientific approved in 2015) and Amulet (made by Abbott and approved in 2021). Other devices are now in research trials.

To learn more about atrial fibrillation, talk to your primary care provider or contact us at the NMMC Heart and Vascular Institute.