Atrial fibrillation (A-fib) is an irregular heart rhythm, also known as a type of arrhythmia. It can interrupt the normal flow of blood in the body and increase the risk of blood clots and stroke.
A-fib is the most common clinical arrhythmia worldwide. It affects up to 3% of the Western population over the age of 20 years, according to estimates. A-fib is most prevalent in older adults, but it can occur at younger ages as well.
A person’s heart comprises four chambers: two upper chambers (the atria) and two lower chambers (the ventricles).
The heartbeat usually starts as a steady pulse in the right atrium. This results in a consistent, regular heartbeat and blood flow between the atria and the ventricles.
However, in people with A-fib, irregular electrical impulses cause the left and right upper chambers to twitch erratically and rapidly. This is called fibrillation.
The resulting arrhythmia may or may not produce symptoms. However, recognizing and treating A-fib early in its development can significantly improve the chance of preventing complications.
In this article, learn about the symptoms, complications, and treatment options associated with A-fib.
A-fib may not cause any symptoms, or the symptoms may only occur intermittently.
Often, the heart rate is higher than usual with A-fib. However, a person’s heart rate will depend on the frequency of the signals experienced by the atria and how rapidly they are conducted to the ventricle.
Some common symptoms include:
- palpitations, or the feeling of an irregular heartbeat
- breathlessness, particularly during exercise or activity
- chest pain, pressure, or discomfort
- low blood pressure
- dizziness, lightheadedness, and fainting
A person with A-fib or suspected A-fib should pay attention to when their symptoms occur or change in severity. Recording these changes may assist doctors in providing a diagnosis and deciding on the best treatment.
Certain factors increase the risk of developing A-fib. These include:
- Age: The older a person is, the higher their risk of A-fib becomes.
- Hypertension: Long-term high blood pressure can add strain to the heart and increase the risk of A-fib.
- Pulmonary embolism: A blood clot in the lung
may increasethe risk of a person developing A-fib.
- Heart disease: People with underlying heart conditions have a higher risk of A-fib. These conditions include:
- Excessive alcohol consumption: Heavy alcohol consumption can increase a person’s risk of developing A-fib.
- Family members with A-fib: People with a family history of A-fib may be
more likelyto experience the condition themselves.
- Sleep apnea: People with this condition, especially when it is severe, have a higher risk of developing A-fib.
- Other chronic conditions: Other long-term medical problems — including thyroid problems, asthma, diabetes, and obesity — may contribute to the risk of A-fib.
The treatment of A-fib aims to improve symptoms and reduce the risk of complications. Prescription medications may be enough to treat symptoms in many people. However, doctors may recommend medical interventions in some circumstances.
Medical professionals will assess a person’s symptoms, lifestyle, underlying health status, and heart function to develop a comprehensive treatment plan.
Treatment may involve the following.
Medications can control a person’s heart rate, prevent clots from forming, and, in some instances, normalize heart rhythm.
Managing heart rate
If the heart rate is high, bringing it down is important to prevent heart failure and reduce the symptoms of A-fib.
Several medications can help by slowing signals that tell the heart to beat. These include:
- beta-blockers, such as metoprolol and atenolol
- calcium channel blockers, such as diltiazem and verapamil
A doctor may prescribe anticoagulant medications, or blood thinners. These medications make it harder for blood to clot.
Taking blood-thinning medications can increase a person’s risk of excessive bleeding. However, for most people, the benefits of preventing blood clots are greater than the risks of bleeding.
A doctor can determine whether or not a person needs to take a blood-thinning medication. They will do this by determining a CHA2DS2-Vasc score.
Some blood-thinning medications include direct-acting oral anticoagulants — including apixaban, rivaroxaban, edoxaban, and dabigatran — and, less commonly, warfarin.
People taking warfarin or another anti-clotting agent should advise any medical professional treating their condition of their current medications. This is especially important during the treatment of other conditions or before surgeries.
Normalizing heart rhythm
Instead of prescribing a heart rate-controlling medication, a doctor may try to return the heart rhythm to normal using medication. This is called chemical, or pharmacologic, cardioversion.
Medications called sodium channel blockers, such as flecainide, and potassium channel blockers, such as amiodarone, are examples of medications that help convert A-fib to a regular heart rhythm. These are anti-arrhythmias.
Often, even after the heart rhythm returns to normal, a person may need to take need blood-thinning medications.
When a person’s condition does not respond positively to medication, additional procedures may be necessary. These may help control the heart rate, normalize the heart rhythm, or prevent complications from A-fib.
Some recommended procedures include:
- Electrical cardioversion: A surgeon will deliver a synchronized electric shock to the heart. This can reset the irregular rhythm to a regular beat. Before carrying out cardioversion, they
will oftenperform a transesophageal echocardiogram. This involves inserting a scope down the throat to produce an image of the heart. A surgeon will carry out this procedure to ensure that no clots are present in the heart. If they find a clot, a doctor will prescribe anticoagulant medication for several weeks to dissolve it. Cardioversion will be possible after the clot has dissolved.
- Catheter ablation: This destroys the tissue that is causing the irregular rhythm. The surgeon may need to repeat this procedure if A-fib returns.
- Surgical ablation: Surgeons can also remove the heart tissue causing the irregular rhythm in an open-heart surgery called a maze procedure. Often, they will only carry out this procedure alongside other heart procedures.
- Pacemaker placement: This device instructs the heart to beat regularly. A surgeon will sometimes place a pacemaker in a person with intermittent A-fib.
When a doctor feels that another condition, such as hyperthyroidism or sleep apnea, is responsible for the A-fib, they will treat the underlying condition alongside the arrhythmia.
Blood can pool in the atria if the heart is not beating regularly. Blood clots can then form in these pools.
A segment of a clot, called an embolus, might break off and travel to different parts of the body through the bloodstream and cause blockages. For example, an embolus can restrict blood flow to the kidneys, intestine, spleen, brain, or lungs. A blood clot can be fatal.
A stroke occurs when a blood clot blocks an artery in the brain and reduces or stops blood flow to part of the brain.
The symptoms of a stroke vary depending on the part of the brain in which the stroke occurs. They can include weakness on one side of the body, vision problems, and speech and movement difficulties.
Stroke is a
A-fib can lead to heart failure, especially when the heart rate is high. When the heart rate is irregular, the amount of blood flowing between the heart’s upper and lower chambers varies for each heartbeat. The heart muscle can tire out from beating too quickly and irregularly.
As a result, the heart may not pump enough blood to the body, and the amount of blood waiting to circulate can instead build up in the lungs and other areas.
A-fib can also worsen the symptoms of any underlying heart failure.
A 2018 study associated A-fib with a higher long-term risk of cognitive decline and dementia. However, according to
Controlling the factors that increase the risk of A-fib may help prevent it. For example, a person can try:
- Managing the diet: Making dietary modifications may
reduce the riskof A-fib and other heart conditions. For example, one reviewof plant-based diets suggested that prioritizing whole food consumption may help a person decrease their blood pressure. High blood pressure is a primary risk factor in A-fib. More research is necessary to assess the potential links between diet and A-fib prevention.
- Avoiding harmful substances: Tobacco, alcohol, and some illicit drugs can damage the heart. With or without a diagnosis of A-fib, eliminating tobacco, reducing the use of mood-altering substances, and moderating alcohol intake are vital for protecting the heart. This is also important in a person who already has A-fib.
- Managing stress: Stress can increase blood pressure and heart rate, which makes the heart work harder. Managing stress levels can help prevent the progression and development of A-fib. Breathing exercises, mindfulness, meditation, and yoga can all help reduce stress.
- Exercising: Having a physically active lifestyle has profound effects on overall cardiovascular health and can help strengthen the heart, thereby reducing the risk of A-fib and other conditions. However, people should be careful not to overexert themselves, as this can increase the risk of A-fib.
A-fib is a condition that causes an irregular heart rhythm. It occurs more often after the age of 65 years, and it may or may not cause symptoms. The condition can lead to a stroke if blood pools in the heart and forms a clot that travels to the brain.
Making lifestyle adjustments can help prevent A-fib. These include prioritizing a heart-healthy diet, limiting alcohol intake, avoiding smoking, maintaining a moderate weight, and getting regular exercise.
Treatment will focus on normalizing the heart rhythm and preventing complications. A doctor may prescribe medications to regulate heart activity and blood-thinning medications to prevent clots. In certain circumstances, they may recommend surgical procedures.