Atrial Fibrillation: Symptoms, Causes & Treatment

What Is Atrial Fibrillation?

Atrial fibrillation (AFib or AF) is a heart rhythm disorder where the heart's upper chambers (atria) beat chaotically and irregularly instead of in a coordinated rhythm. This causes the heart to pump blood less efficiently and significantly increases the risk of blood clots, stroke, heart failure, and other heart-related complications.

Atrial fibrillation is the most common sustained cardiac arrhythmia worldwide, affecting approximately 2-4% of the adult population. The prevalence increases dramatically with age, affecting up to 15% of people over 80 years old. As the global population ages, AFib is becoming an increasingly significant public health concern, with estimates suggesting that the number of people affected will double by 2050.

The heart is a muscular organ that pumps blood throughout the body. It consists of four chambers: two upper chambers called atria and two lower chambers called ventricles. In a healthy heart, each heartbeat begins with an electrical signal from the sinus node in the right atrium. This signal travels through the heart in an organized pattern, causing the atria to contract first, followed by the ventricles. This coordinated contraction ensures that blood fills the heart chambers properly before being pumped out.

In atrial fibrillation, the electrical signals in the atria become disorganized and chaotic. Instead of a single coordinated signal, multiple electrical impulses fire simultaneously from different locations in the atria. This causes the atria to quiver (fibrillate) rather than contract effectively. As a result, the ventricles receive irregular signals and beat in an uncoordinated, often rapid manner. The heart can still function during AFib, typically operating at about 80% efficiency, but this becomes physically demanding over time and increases the risk of complications.

Types of Atrial Fibrillation

Understanding the different types of atrial fibrillation is important because the classification affects treatment decisions and prognosis. Cardiologists categorize AFib based on how long episodes last and whether they resolve spontaneously or require intervention.

Paroxysmal atrial fibrillation occurs in episodes that start and stop on their own, typically lasting less than 7 days and often resolving within 24-48 hours. People with paroxysmal AFib may experience episodes ranging from a few seconds to several days. Between episodes, the heart rhythm returns to normal. However, over time, paroxysmal AFib often progresses to more persistent forms of the condition.

Persistent atrial fibrillation lasts longer than 7 days and does not resolve spontaneously. It requires medical intervention—either medications or cardioversion (an electrical shock to restore normal rhythm)—to terminate the episode. Persistent AFib can recur even after successful treatment.

Long-standing persistent atrial fibrillation has been continuous for more than 12 months. At this stage, restoring and maintaining normal rhythm becomes increasingly difficult, though rhythm control strategies may still be attempted in selected patients.

Permanent atrial fibrillation is diagnosed when a joint decision has been made by the patient and physician to stop attempting to restore or maintain normal rhythm. Treatment focuses on controlling heart rate and preventing complications rather than restoring normal rhythm. It's important to note that "permanent" is a clinical decision rather than a pathophysiological state—some patients previously considered permanent may later undergo successful rhythm control procedures.

What Are the Symptoms of Atrial Fibrillation?

Common symptoms of atrial fibrillation include irregular or rapid heartbeat (palpitations), shortness of breath, fatigue, dizziness, chest discomfort, and reduced exercise tolerance. However, some people have no symptoms at all and their AFib is discovered incidentally during medical examinations.

The symptoms of atrial fibrillation vary widely between individuals. Some people experience severe, debilitating symptoms that significantly impact their quality of life, while others have no symptoms whatsoever. This variability is one reason why AFib can go undetected for long periods, sometimes only being discovered after a stroke or other serious complication.

The presence or severity of symptoms does not correlate with the risk of complications. A person with no symptoms still faces the same increased stroke risk as someone with severe symptoms. This is why screening and regular heart rhythm checks are important, particularly in older adults and those with risk factors for AFib.

Common Symptoms

The most frequently reported symptoms of atrial fibrillation include:

• Palpitations: A sensation of the heart beating hard, fast, fluttering, or skipping beats. Many describe it as feeling like the heart is "racing" or "pounding" in the chest.
• Irregular pulse: When checking your pulse at the wrist or neck, you may notice it feels chaotic or unpredictable rather than steady and rhythmic.
• Shortness of breath: Difficulty breathing, especially during physical activity or when lying flat. You may feel winded with minimal exertion.
• Fatigue: Unusual tiredness and lack of energy, even after adequate rest. This occurs because the heart cannot pump blood efficiently.
• Weakness: A general feeling of reduced strength and stamina.
• Dizziness or lightheadedness: Feeling unsteady or like you might faint.
• Chest discomfort: Pressure, tightness, or pain in the chest area.
• Reduced exercise tolerance: Difficulty performing physical activities that were previously manageable.

Less Common Symptoms

Some people with atrial fibrillation experience additional symptoms that may not immediately be recognized as heart-related:

• Sweating: Particularly cold sweats unrelated to physical exertion or temperature.
• Nausea: Feeling queasy or sick to the stomach.
• Fainting (syncope): Loss of consciousness, which requires immediate medical attention.
• Anxiety: A feeling of impending doom or intense worry, sometimes triggered by the sensation of abnormal heart rhythm.
• Frequent urination: AFib can cause the heart to release hormones that increase urine production.

When Should You See a Doctor for Atrial Fibrillation?

Seek immediate emergency care if you experience severe chest pain, difficulty breathing, signs of stroke (facial drooping, arm weakness, speech difficulties), or fainting. Contact your doctor promptly if you notice irregular heartbeat, unexplained fatigue, or AFib episodes lasting longer than 24 hours.

Recognizing when to seek medical care for atrial fibrillation symptoms is crucial for preventing serious complications. While AFib itself is rarely immediately life-threatening, it can lead to serious complications that require urgent attention. Understanding the warning signs helps you respond appropriately and get the care you need.

Emergency Situations - Call Emergency Services Immediately

Some situations associated with atrial fibrillation require immediate emergency medical care. Do not delay seeking help if you experience any of the following:

Urgent Care - Seek Medical Attention Promptly

Contact a healthcare provider or seek urgent care if you experience:

• A heart rate that is significantly higher than normal at rest or during minimal activity
• AFib symptoms lasting longer than 24 hours without improvement
• Unexplained weight gain combined with swelling in your legs, ankles, or feet
• Worsening shortness of breath compared to your baseline
• Symptoms persisting despite taking your prescribed medications

Routine Care - Schedule an Appointment

If you have been diagnosed with permanent AFib, contact your healthcare provider if you notice:

• Episodes becoming more frequent or lasting longer
• New symptoms developing or existing symptoms worsening
• Side effects from your medications
• Questions about your treatment plan or lifestyle modifications

What Causes Atrial Fibrillation?

Atrial fibrillation is often caused by damage to the heart's electrical system, commonly from conditions such as high blood pressure, coronary artery disease, heart valve disorders, or heart failure. Other causes include hyperthyroidism, sleep apnea, excessive alcohol consumption, and sometimes no identifiable cause (lone AFib).

The exact cause of atrial fibrillation is not always clear, but researchers have identified numerous factors that can damage or alter the heart's electrical system and trigger abnormal rhythms. In many cases, AFib results from a combination of underlying conditions and lifestyle factors rather than a single cause. Understanding these causes helps identify who is at risk and guides treatment decisions.

More than half of all people diagnosed with atrial fibrillation have other underlying medical conditions, particularly cardiovascular diseases. The association between AFib and these conditions is bidirectional—the underlying conditions can cause AFib, and AFib can worsen these conditions.

Cardiovascular Causes

Heart and blood vessel conditions are the most common causes of atrial fibrillation:

• High blood pressure (hypertension): The most common risk factor for AFib. Chronic high blood pressure causes the heart muscle to thicken and stiffen, creating conditions favorable for abnormal electrical activity. Controlling blood pressure is one of the most important steps in AFib prevention and management.
• Coronary artery disease: Narrowed or blocked arteries reduce blood flow to the heart muscle, potentially damaging the tissue that conducts electrical signals.
• Heart failure: When the heart cannot pump blood effectively, the resulting strain on the heart chambers can trigger AFib. Conversely, AFib can lead to heart failure over time—creating a dangerous cycle.
• Heart valve disease: Abnormal heart valves, particularly mitral valve stenosis or regurgitation, alter blood flow patterns and can cause the atria to enlarge, predisposing to AFib.
• Cardiomyopathy: Diseases of the heart muscle can disrupt normal electrical conduction.
• Previous heart surgery: Cardiac surgery, especially procedures involving the atria, can create scar tissue that interferes with normal electrical pathways.

Non-Cardiovascular Causes

Several conditions unrelated to the heart structure itself can trigger or contribute to atrial fibrillation:

• Hyperthyroidism: An overactive thyroid gland increases metabolic rate and can overstimulate the heart, leading to AFib. Thyroid function should be checked in all patients newly diagnosed with AFib.
• Sleep apnea: Obstructive sleep apnea causes repeated drops in blood oxygen levels during sleep, placing stress on the heart and increasing AFib risk. Treating sleep apnea can significantly reduce AFib episodes.
• Obesity: Excess weight contributes to AFib through multiple mechanisms, including increased inflammation, sleep apnea, and metabolic disturbances. Weight loss has been shown to reduce AFib burden significantly.
• Diabetes: High blood sugar levels can damage blood vessels and nerves that control the heart rhythm.
• Chronic kidney disease: Kidney dysfunction alters electrolyte balance and increases cardiovascular stress.

Lifestyle and Environmental Triggers

Certain behaviors and substances can trigger AFib episodes, particularly in susceptible individuals:

• Alcohol consumption: Even moderate alcohol intake can trigger AFib in some people. "Holiday heart syndrome" refers to AFib episodes that occur after heavy drinking.
• Caffeine: While moderate caffeine intake is generally safe for most people, excessive consumption may trigger episodes in some individuals.
• Stimulant use: Certain medications, illicit drugs, and supplements can trigger abnormal heart rhythms.
• Extreme physical exertion: Elite endurance athletes have a higher incidence of AFib, possibly due to structural changes in the heart from intense training.
• Stress: Physical or emotional stress can trigger AFib episodes through activation of the sympathetic nervous system.
• Infections: Acute illnesses, particularly those causing fever, can precipitate AFib episodes.

How Is Atrial Fibrillation Diagnosed?

Atrial fibrillation is primarily diagnosed using an electrocardiogram (ECG/EKG), which shows the characteristic irregular heart rhythm. Additional tests may include Holter monitoring, echocardiography, and blood tests to identify underlying causes such as thyroid disorders or electrolyte imbalances.

Diagnosing atrial fibrillation begins with a thorough medical evaluation that includes reviewing your symptoms, medical history, and risk factors. Because AFib can occur intermittently, capturing the abnormal rhythm on testing can sometimes be challenging. Multiple diagnostic approaches may be needed, especially for paroxysmal AFib.

Electrocardiogram (ECG/EKG)

The electrocardiogram is the primary diagnostic tool for atrial fibrillation. This painless, non-invasive test records the electrical activity of your heart through small electrode patches placed on your chest, arms, and legs. An ECG can be completed in minutes and clearly shows whether the heart rhythm is irregular.

On an ECG, atrial fibrillation appears as an irregularly irregular rhythm without organized P waves (the electrical signal representing atrial contraction). Instead, there are chaotic, rapid waves called fibrillatory or "f" waves. The ventricular response (how fast the main pumping chambers beat) can vary widely.

Extended Monitoring

Because paroxysmal AFib may not occur during a routine office ECG, longer monitoring periods are often necessary:

• Holter monitor: A portable ECG device worn continuously for 24-48 hours that records every heartbeat. Useful for detecting intermittent arrhythmias.
• Event recorder: A portable device worn for weeks that you activate when you feel symptoms. Some devices automatically detect and record abnormal rhythms.
• Implantable loop recorder: A small device inserted under the skin that can monitor heart rhythm continuously for up to three years. Used when AFib is strongly suspected but not captured by other methods.
• Smartwatch ECG: Some consumer devices can detect irregular rhythms and record single-lead ECGs, though these require confirmation with medical-grade equipment.

Additional Tests

Once AFib is confirmed, additional testing helps identify underlying causes and guides treatment decisions:

• Echocardiogram: An ultrasound of the heart that shows the size and function of the heart chambers, valve function, and any structural abnormalities. It can also detect blood clots in the heart.
• Blood tests: Used to check thyroid function, kidney function, electrolyte levels, complete blood count, and markers of cardiac damage.
• Chest X-ray: Can reveal heart enlargement, lung congestion, or other contributing conditions.
• Sleep study: May be recommended if sleep apnea is suspected.
• Stress testing: Exercise or pharmacological stress tests may be used to evaluate how the heart responds to physical activity.

How Is Atrial Fibrillation Treated?

Treatment for atrial fibrillation focuses on three goals: controlling heart rate, restoring normal rhythm when possible, and preventing blood clots to reduce stroke risk. Treatment options include anticoagulant medications, rate-control drugs (beta-blockers, calcium channel blockers), antiarrhythmic medications, cardioversion, and catheter ablation.

Atrial fibrillation treatment is highly individualized, taking into account the type of AFib, symptom severity, underlying health conditions, stroke risk, and patient preferences. The treatment approach may involve one or more of the following strategies, and many patients require a combination of therapies.

Treatment goals in atrial fibrillation management include:

1. Stroke prevention - The most important goal, as AFib significantly increases stroke risk
2. Rate control - Keeping the heart rate within a normal range
3. Rhythm control - Attempting to restore and maintain normal sinus rhythm
4. Symptom management - Improving quality of life
5. Treating underlying conditions - Addressing factors contributing to AFib

Anticoagulation Therapy (Blood Thinners)

Preventing blood clots and stroke is the cornerstone of AFib treatment. When the atria fibrillate, blood can pool and form clots that may travel to the brain and cause a stroke. Anticoagulation therapy reduces stroke risk by 60-70% and is recommended for most AFib patients based on their individual stroke risk assessment.

The CHA₂DS₂-VASc score helps determine who needs anticoagulation by assessing risk factors including heart failure, hypertension, age, diabetes, prior stroke, vascular disease, and sex. Most people with a score of 2 or higher benefit from anticoagulation.

Available anticoagulant options include:

• Direct oral anticoagulants (DOACs): These medications (apixaban, rivaroxaban, dabigatran, edoxaban) are now preferred over warfarin for most patients. They work by directly inhibiting specific clotting factors, have predictable effects, don't require regular blood monitoring, and have fewer drug and food interactions.
• Warfarin: An older anticoagulant that remains appropriate for certain patients, particularly those with mechanical heart valves. Requires regular blood tests (INR monitoring) and careful attention to diet and drug interactions.

Rate Control Medications

Rate control aims to keep the ventricular rate (how fast the lower chambers beat) within a normal range, typically below 110 beats per minute at rest for most patients, and sometimes tighter control below 80 beats per minute for those with symptoms.

• Beta-blockers (metoprolol, atenolol, bisoprolol): Slow the heart rate by blocking the effects of adrenaline. Often the first choice for rate control.
• Calcium channel blockers (diltiazem, verapamil): Slow electrical conduction through the heart. Cannot be used with severe heart failure.
• Digoxin: May be added when other medications don't adequately control rate. Most effective at controlling rate at rest rather than during activity.

Rhythm Control Strategies

Rhythm control aims to restore and maintain normal sinus rhythm. This approach may be preferred for patients with significant symptoms, those with new-onset AFib, and younger patients. Options include:

Antiarrhythmic Medications

These drugs help maintain normal rhythm after conversion:

• Flecainide and propafenone: Class IC antiarrhythmics, typically used in patients without significant structural heart disease
• Amiodarone: The most effective antiarrhythmic drug but with significant potential side effects requiring regular monitoring
• Dronedarone: Similar to amiodarone with fewer side effects but less effective, not suitable for patients with heart failure
• Sotalol and dofetilide: Class III antiarrhythmics requiring careful initiation due to proarrhythmic risk

Cardioversion

Electrical cardioversion uses a controlled electrical shock delivered through paddles or patches on the chest to reset the heart's rhythm. It is performed under brief anesthesia and is often effective at restoring normal rhythm, though AFib frequently recurs without additional treatment.

Pharmacological cardioversion uses intravenous medications to restore normal rhythm. Vernakalant (Brinavess) is one such medication that can be effective, particularly for recent-onset AFib.

Catheter Ablation

Catheter ablation is a minimally invasive procedure where thin, flexible tubes (catheters) are guided through blood vessels to the heart. The procedure targets and destroys small areas of heart tissue that are generating abnormal electrical signals—most commonly around the pulmonary veins where AFib often originates.

Ablation can be performed using:

• Radiofrequency ablation: Uses heat to create small scars
• Cryoablation: Uses extreme cold (balloon-based technique)
• Pulsed field ablation: A newer technique using electrical fields

Success rates for catheter ablation are approximately 60-80% for paroxysmal AFib and somewhat lower for persistent AFib. Some patients may require more than one procedure. Ablation is particularly effective for younger patients with paroxysmal AFib and minimal structural heart disease.

Surgical Options

For patients undergoing open heart surgery for other reasons (such as valve repair), surgical ablation can be performed simultaneously. The Maze procedure creates a pattern of surgical scars that interrupt abnormal electrical pathways.

What Can You Do to Manage Atrial Fibrillation?

Lifestyle modifications that help manage AFib include maintaining a healthy weight, limiting alcohol consumption, exercising regularly (with doctor's guidance), treating sleep apnea, managing stress, controlling blood pressure and diabetes, and avoiding AFib triggers. These changes can reduce episode frequency and improve overall heart health.

While medications and procedures play important roles in AFib management, lifestyle modifications are equally crucial. Research shows that comprehensive lifestyle changes can reduce AFib burden significantly and may even reduce the need for medications or procedures.

Weight Management

Maintaining a healthy weight is one of the most impactful changes you can make. Studies show that weight loss of 10% or more can reduce AFib episodes significantly and may even lead to long-term freedom from AFib in some patients. Obesity contributes to AFib through multiple mechanisms, including increased inflammation, sleep apnea, and metabolic dysfunction.

Alcohol Moderation

Alcohol is a well-known trigger for AFib episodes. Even moderate drinking increases AFib risk, and heavy drinking can trigger "holiday heart syndrome"—AFib episodes following alcohol consumption. Complete abstinence from alcohol has been shown to reduce AFib recurrence in people who drink regularly.

Exercise

Regular moderate exercise improves cardiovascular health and can help manage AFib. However, the relationship between exercise and AFib is complex—while moderate activity is beneficial, extreme endurance training may actually increase AFib risk. Work with your healthcare provider to develop an appropriate exercise plan.

Sleep Apnea Treatment

Obstructive sleep apnea significantly increases AFib risk and reduces the effectiveness of AFib treatments. If you snore heavily, wake up feeling unrefreshed, or have been told you stop breathing during sleep, discuss sleep apnea testing with your doctor. CPAP therapy can substantially reduce AFib burden in people with sleep apnea.

Stress Management

Stress and strong emotions can trigger AFib episodes. Techniques such as meditation, deep breathing exercises, yoga, and cognitive behavioral therapy can help manage stress. Some people find that identifying and avoiding specific triggers helps reduce episode frequency.

Managing Other Conditions

Optimal control of conditions that contribute to AFib is essential:

• Blood pressure control: Target blood pressure below 130/80 mmHg for most people with AFib
• Diabetes management: Good blood sugar control reduces cardiovascular complications
• Thyroid function: Ensure thyroid conditions are properly treated
• Cholesterol management: Control LDL cholesterol to reduce cardiovascular risk

What Are the Complications of Atrial Fibrillation?

The most serious complication of atrial fibrillation is stroke, which occurs when blood clots form in the heart and travel to the brain. AFib increases stroke risk approximately five-fold. Other complications include heart failure, reduced quality of life, and cognitive decline. Proper treatment significantly reduces these risks.

While atrial fibrillation itself is rarely immediately life-threatening, it can lead to serious complications if not properly managed. Understanding these risks emphasizes the importance of consistent treatment and monitoring.

Stroke

Stroke is the most feared complication of atrial fibrillation. When the atria fibrillate rather than contract normally, blood can pool in a pouch called the left atrial appendage, where clots may form. If a clot breaks loose and travels through the bloodstream to the brain, it can block blood flow and cause a stroke.

AFib-related strokes tend to be more severe than strokes from other causes, with higher rates of disability and death. This is why stroke prevention through anticoagulation is the cornerstone of AFib management. With appropriate anticoagulation, stroke risk is reduced by 60-70%.

Heart Failure

The constant rapid and irregular beating of AFib places strain on the heart muscle over time. This can lead to or worsen heart failure, a condition where the heart cannot pump blood effectively to meet the body's needs. AFib and heart failure often coexist and worsen each other—a phenomenon sometimes called the "chicken and egg" relationship.

Other Complications

• Systemic embolism: Clots can travel to other parts of the body besides the brain, blocking blood flow to the limbs, kidneys, or intestines
• Cognitive decline: Research suggests AFib is associated with an increased risk of dementia and cognitive impairment, possibly related to reduced blood flow or small, undetected strokes
• Tachycardia-induced cardiomyopathy: Prolonged rapid heart rates can weaken the heart muscle
• Reduced quality of life: Symptoms such as fatigue, shortness of breath, and exercise intolerance can significantly impact daily activities

Living with Atrial Fibrillation

Living well with atrial fibrillation is possible with proper treatment, lifestyle modifications, and regular medical care. Many people with AFib lead full, active lives. Open communication with your healthcare team, medication adherence, and understanding your condition are key to successful management.

A diagnosis of atrial fibrillation can feel overwhelming, but it's important to know that the condition is manageable. With appropriate treatment and self-care, most people with AFib can maintain good quality of life and continue their normal activities.

Emotional Impact

It's common to experience anxiety, worry, or depression after an AFib diagnosis or during episodes. The unpredictability of paroxysmal AFib can be particularly stressful. Some people begin avoiding activities they previously enjoyed out of fear of triggering an episode.

If anxiety about your condition is affecting your quality of life, discuss this with your healthcare provider. Cognitive behavioral therapy (CBT) has been shown to help people with AFib manage anxiety and maintain active, fulfilling lives. Support groups and connecting with others who have AFib can also be valuable.

Ongoing Care

Regular follow-up with your healthcare provider is essential for optimal AFib management:

• Monitor your symptoms and report changes
• Take all medications as prescribed
• Attend scheduled appointments and testing
• Know when to seek urgent care
• Stay informed about your condition and treatment options

Travel Considerations

Most people with well-controlled AFib can travel safely. Consider the following:

• Carry a list of your medications and your doctor's contact information
• Bring adequate medication supplies plus extra in case of delays
• Stay hydrated, especially during flights
• Know how to access medical care at your destination
• If traveling internationally, research local emergency services and hospitals