Atrial Fibrillation Facts
Atrial fibrillation is an abnormal heart rhythm with very fast and irregular heartbeats. Abnormal electrical impulses throughout the upper heart chambers (atria) make the atria fibrillate, or quiver. The impulses also cause the ventricles (lower chambers) to pump faster than normal. Prolonged afib prevents the heart from pumping enough blood into the large aortic artery to the rest of the body. AF is another common abbreviation for atrial fibrillation.
Essential atrial fibrillation facts to know:
Afib life expectancy is shorter the longer the condition goes untreated, due to an increased risk of stroke and other problems.
Afib causes are oftentimes directly related to problems with the heart itself, from either structural defects or damage from other diseases or even heart surgery.
Afib may be a one- or two-time event or it may be recurrent and last for years.
Living with afib is possible with medication, cardioversion, cardiac ablation, pacemaker therapy, or a combination of these measures to restore and maintain a more normal heart rate and rhythm, thereby reducing stroke risk.
Afib diagnosis includes classification into one (or more) of these types:
First-diagnosed afib applies to patients when they are first diagnosed with atrial fibrillation, according to standard AF diagnostic guidelines, regardless of symptoms and number or duration of episodes.
Asymptomatic afib, also known as silent afib, does not cause symptoms. Afib may be an incidental EKG finding.
Paroxysmal afib is two or more episodes that end spontaneously within seven days.
Persistent afib is two or more episodes that last seven or more days.
Long-standing persistent afib is afib that continues one year or longer.
Permanent afib is a patient- and doctor-reported type of afib in which someone is no longer pursuing treatment to restore a normal rhythm.
Two to 6 million people in the United States have atrial fibrillation, the most common chronic arrhythmia in the world.
Afib affects 9% of the U.S. population older than 65.
As risk of afib increases with age, about 12 million of the U.S. population may have atrial fibrillation by 2030.
Afib is more common in White than Black Americans and other races.
Biological sex does not appear to be a risk factor for afib.
Patients with afib do not die from the fast and irregular heart rhythm itself, but afib patients have a five-fold higher risk of stroke compared to people without afib. This is because during atrial fibrillation, blood does not completely empty into the left ventricle. Blood left behind in the atria can pool and form a clot (thrombus). If part of the clot breaks away, it is an embolus, which can move into circulation and become lodged in a blood vessel in the brain, causing stroke.
As stroke is one of the leading causes of death and disability in the United States, it’s especially important for afib patients and their loved ones to know the signs and symptoms of stroke: sudden facial numbness or drooping, arm or leg weakness, speech impairment, vision problems, and asymmetry (one side of the body affected).
Afib also carries a three-fold higher risk of heart failure and two-fold higher risk of dementia.
Conditions related to atrial fibrillation include:
Atrial flutter: An electrical problem in the heart that causes the atria to beat very fast like in afib, but the beats are steady. It also increases the risk of stroke.
Sinus sick syndrome: A group of symptoms that arise from a problem with the heart’s normal pacemaker, the sinus node. The heart rate can change from slower than normal (bradycardia) to faster than normal (tachycardia) to atrial fibrillation and flutter.
Sinus tachycardia: A faster-than-normal heart rate that is usually harmless and occurs with fever, excitement, and intense exercise. Treatable conditions that can cause sinus tachycardia include anemia and hyperthyroidism.
Ventricular arrhythmias: These include ventricular tachycardia and ventricular fibrillation.
The effect of afib on quality of life (QoL) varies considerably depending on the type of afib and how well it is controlled with standard treatments. Doctors and caregivers study health-related QoL (HRQoL) to determine the impact of afib and its treatment on the patient’s perception of their physical, mental and social health and well-being. HRQoL also gives providers insight into the benefits (e.g., symptom control) and risks (e.g., side effects) of different treatments.
Most patients with afib have a reduced HRQoL according to patient-reported answers to standard and afib-specific questionnaires.
Factors that can decrease HRQoL scores include:
Comorbid conditions such as heart failure
Decreased exercise tolerance
Psychological distress such as anxiety
There is a direct correlation between the patient’s perception of their mental well-being and their afib symptoms. In other words, negative emotions—worry, sadness, anger—are associated with patients perceiving their symptoms as more severe (lower HRQoL scores), while positive emotions—happiness, excitement, optimism—are associated with less symptom severity (higher HRQoL scores).
Atrial fibrillation initially starts from premature contraction of the atria triggered by electrical impulses arising from where the pulmonary veins (PVs) meet the left atrium. Impulses from the PVs and other focal points in the heart contribute to maintaining fibrillation, especially in patients with paroxysmal afib. Arrhythmia experts find multiple electrical impulses—wavelets—throughout the atria. One theory is these wavelets keep the atria fibrillating. Extended fibrillation damages atrial heart muscle over time, which contributes to afib disease.
Factors and conditions that can increase the risk of developing afib include:
Heart damage from cardiac surgery
Stress on physiological processes including older age, chronic lung disease, overactive thyroid, obesity, and metabolic syndrome
Known mutations in specific genes can cause familial, or hereditary atrial fibrillation, but this accounts for a small percentage of afib patients. Certain variations in several other genes influence the risk of developing afib. However, of the 2 to 6 million people with afib, the number who have it due to gene variation is not known.
Known triggers of an afib episode are:
The most accurate test to diagnose afib is a 12-lead electrocardiogram (EKG). A normal heart rate for an adult is 60 to 100 beats per minute; the beat occurs with a steady frequency and electrical pattern. With afib, the atrial rhythm is irregular and the rate is 300 to 700 beats per minute. The ventricular rhythm may also be irregular with a rate between 120 to 180 beats per minute.
Doctors also consider the patient’s symptoms and may run tests to exclude other arrhythmias.
Doctors approach atrial fibrillation with these goals and treatments:
Slowing the patient’s heart rate: beta blockers and calcium channel blockers
Reducing the risk of blood clots and stroke: vitamin K antagonists (e.g., warfarin); anticoagulants (blood thinners); antiplatelet compounds such as aspirin; and left atrial appendage closure, a minimally invasive procedure
Restoring and maintaining a normal heart rhythm: antiarrhythmic drugs, cardioversion, pacemakers, cardiac ablation, combination ablation and pacemaker therapy, and the maze procedure
For afib patients who are medically unstable, electrical cardioversion to restore a sinus rhythm is the first-line therapy.
Some cases of afib cannot be avoided, such as those caused by congenital heart defects. However, the American Heart Association advises people to focus on “Life’s Simple Seven” to prevent afib, including blood pressure, weight, glucose, cholesterol, smoking, diet and physical activity.
September is Atrial Fibrillation Awareness Month. Learn more about afib and afib awareness from the American Heart Association.