Atrial fibrillation (AFib) is an abnormal or rapid heart rate. This is a common but serious type of arrhythmia. It occurs when the heart’s upper and lower chambers beat out of coordination. This causes poor blood flow and increases the risk of blood clots, stroke, and heart failure.
In most people, heart disease or a heart abnormality causes AFib. But you can have AFib without having any underlying heart disease. This is often known as lone atrial fibrillation (lone AF).
There is some debate among doctors about the definition of lone AF. The term has been used to describe different characteristics since it was first identified in 1953. Some doctors think it shouldn’t be distinguished as a type of AFib at all. According to medical guidelines from the American College of Cardiology and the American Heart Association, the term is currently used for people with AFib who have no history or echocardiographic evidence of cardiovascular or pulmonary disease. Also included would be the following:
- don’t have heart disease, such as hypertension
- are 60 years of age or younger and don’t have any related conditions, such as heart failure, chronic obstructive pulmonary disease (COPD), diabetes, hyperthyroidism, acute infections, recent cardiothoracic or abdominal surgery, and systemic inflammatory disease.
Other guidelines from the European Society of Cardiology say that doctors should avoid the term until more is understood about the different causes and types of AFib.
AFib can be asymptomatic, meaning you don’t experience any symptoms. This means that you can have AFib and not know it. Your doctor may discover an irregular heart rate during a routine physical examination. When symptoms do occur, they can include:
- heart palpitations or flutter
- shortness of breath
- chest pain
Lone AF symptoms are often sporadic. Heart palpitations or other related symptoms may only last a few minutes. Symptoms could return hours, days, weeks, or months later.
AFib is most often linked to associated or underlying heart disease or abnormalities, such as:
- high blood pressure
- coronary artery disease
- abnormal heart valves
- congenital heart defect
The risk of AFib increases with age. There’s also a higher risk if you're obese or have a family history of AFib.
But lone AF is defined by AFib without any of these other conditions. The exact cause of lone AF is unclear. But doctors believe the following factors may contribute to these irregular heart rhythms:
- viral infections
- sleep apnea
- use of stimulants, such as medication, alcohol, or tobacco
- physical or emotional stress
- overactive thyroid gland
- a family history of lone AF
Men are also more likely than women to have lone AF.
If you have an irregular heart rhythm or are experiencing symptoms of AFib, your doctor may recommend the following tests:
- an electrocardiogram, to check electrical signals traveling to your heart
- an echocardiogram, which creates an image of your heart
- a cardiac event recorder, to track your heart activity over several weeks
- blood tests
- a chest X-ray
- a stress test, to observe your heart function during physical activity
These tests will help your doctor find heart disease or any related conditions that could be causing your AFib. Your doctor may diagnose you with lone AF if you:
- don’t have heart disease
- are age 60 or younger and don’t have any related diseases
Treatment for AFib is usually based on its underlying cause. But because the cause of lone AF is often unknown, it can be challenging for you and your doctor to determine the right treatment.
Sometimes, an overactive thyroid gland or sleep apnea causes lone AF. In this case, restoring normal rhythm involves properly diagnosing and treating these conditions. If your doctor thinks alcohol, nicotine, or coffee is the culprit you may need to reduce these triggers to stop arrhythmias.
If you exercise heavily, your doctor may ask you to cut back on physical activity to see if your condition improves. Physical stress can trigger lone AF. Emotional stress can too, so your doctor may ask about your mental health. If necessary, your doctor can make recommendations for reducing emotional stress.
Some therapies and drugs that are used for other types of AFib do not treat lone AF. These include therapies such as electrical cardioversion and magnesium injections.
Blood-thinning medications are often given to people with AFib. But people with lone AF don’t usually need anticoagulation therapy because they have a lower risk of stroke.
The long-term outlook for lone AF is positive. People with lone AF tend to have a lower risk of stroke, a common complication with other types of AFib.
But people with lone AF can still develop heart problems, moving them out of the lone AF category. You should periodically follow up with your doctor if you have lone AF. This allows your doctor to check for any developing heart problems.
If you have symptoms of AFib, it’s important to seek medical help, identify any underlying causes, and make lifestyle adjustments to avoid atrial fibrillation triggers. These measures can help reduce heart arrhythmias.