Your heart beats roughly 100,000 times a day in a coordinated rhythm that most people never notice. When that rhythm breaks down — when the upper chambers of the heart quiver chaotically instead of contracting in sync — the result is atrial fibrillation, or AFib.

AFib is the most common sustained heart rhythm disorder in the United States, affecting more than 6 million Americans. It is also one of the most underdiagnosed — because many people have no symptoms at all, or dismiss what they feel as stress or aging.

At Manatee Primary Care in Bradenton, FL, we screen for and manage AFib as part of comprehensive cardiovascular care. Here is what every patient should know.

The heart has four chambers. The two upper chambers (atria) normally receive blood and contract in a coordinated way to push it into the lower chambers (ventricles), which then pump it to the lungs and body.

In AFib, the electrical signals in the atria fire chaotically — hundreds of times per minute — causing them to quiver rather than contract effectively. The ventricles respond irregularly, producing the characteristic irregular, often rapid heartbeat of AFib.

This disorganized rhythm has two major consequences:

1. Reduced cardiac efficiency: The heart pumps less effectively, which can cause fatigue, shortness of breath, and exercise intolerance
2. Blood pooling in the atria: When the atria don't contract fully, blood can pool and form clots — particularly in a small pouch called the left atrial appendage. If a clot breaks loose and travels to the brain, the result is a stroke

AFib is classified by how long episodes last:

• Paroxysmal AFib: Episodes come and go, typically lasting less than 7 days and often resolving on their own
• Persistent AFib: Episodes last more than 7 days and require treatment to restore normal rhythm
• Long-standing persistent AFib: Continuous AFib lasting more than 12 months
• Permanent AFib: When the decision has been made not to pursue rhythm restoration and rate control becomes the primary goal

AFib presents very differently from person to person. Common symptoms include:

• Palpitations — a fluttering, racing, or irregular heartbeat
• Fatigue — often disproportionate to activity level
• Shortness of breath — especially with exertion
• Dizziness or lightheadedness
• Chest discomfort or pressure
• Reduced exercise tolerance

However, up to 30% of people with AFib have no symptoms at all. Their AFib is discovered incidentally — on an EKG done for another reason, or increasingly, through wearable devices like smartwatches.

Asymptomatic AFib is not benign. The stroke risk is the same regardless of whether you feel the arrhythmia.

AFib becomes more common with age — it affects about 1 in 10 people over 80. Other risk factors include:

• High blood pressure (the single most modifiable risk factor)
• Heart disease (coronary artery disease, heart failure, valve disease)
• Obesity
• Sleep apnea
• Diabetes
• Thyroid disease (particularly hyperthyroidism)
• Excessive alcohol use ("holiday heart syndrome")
• Chronic kidney disease
• Family history of AFib

Addressing these underlying conditions is a cornerstone of AFib management.

People with AFib have a 5-fold higher risk of stroke compared to those without it. AFib-related strokes tend to be more severe and more likely to be fatal or disabling than strokes from other causes.

The mechanism: blood pooling in the left atrial appendage forms clots. When a clot travels to the brain, it blocks blood flow — causing a stroke.

Stroke risk in AFib is estimated using the CHA₂DS₂-VASc score, which accounts for:

• Congestive heart failure
• Hypertension
• Age ≥75 (double weight)
• Diabetes
• Stroke/TIA history (double weight)
• Vascular disease
• Age 65–74
• Sex category (female)

A score of 2 or higher in men (or 3 or higher in women) generally warrants anticoagulation therapy.

AFib is diagnosed with an electrocardiogram (EKG) — a simple, painless test that records the heart's electrical activity. The characteristic finding is an irregularly irregular rhythm with absent P waves.

Because paroxysmal AFib comes and goes, a single EKG may miss it. Additional monitoring options include:

• Holter monitor: Continuous EKG recording for 24–48 hours
• Event monitor: Worn for weeks; records when symptoms occur
• Implantable loop recorder: A small device placed under the skin that monitors rhythm for up to 3 years
• Wearable devices: Smartwatches with ECG capability (Apple Watch, Fitbit) can detect AFib and prompt medical evaluation

When AFib is found, we also evaluate for underlying causes with blood tests (thyroid function, complete blood count, metabolic panel), an echocardiogram to assess heart structure, and a review of medications and lifestyle factors.

AFib management has three primary goals:

For most patients with a meaningful CHA₂DS₂-VASc score, anticoagulation (blood thinners) is the most important intervention. Options include:

• Direct oral anticoagulants (DOACs): Apixaban (Eliquis), rivaroxaban (Xarelto), dabigatran (Pradaxa), and edoxaban (Savaysa) are now preferred over warfarin for most patients. They require no routine INR monitoring and have a more predictable effect
• Warfarin: Still used in certain situations, particularly with mechanical heart valves or significant kidney disease. Requires regular INR blood tests
• Left atrial appendage closure (Watchman device): A catheter-based procedure that seals off the left atrial appendage — an option for patients who cannot tolerate long-term anticoagulation

Controlling how fast the ventricles beat reduces symptoms and protects the heart from the long-term effects of a rapid rate. Medications used include:

• Beta-blockers (metoprolol, atenolol, carvedilol)
• Calcium channel blockers (diltiazem, verapamil)
• Digoxin (less commonly used, typically in heart failure)

The target resting heart rate is generally below 80–110 beats per minute, depending on symptoms and overall function.

Restoring and maintaining normal sinus rhythm is not always necessary but can significantly improve symptoms and quality of life. Options include:

• Cardioversion: An electrical shock delivered under sedation to reset the heart's rhythm. Often effective short-term but AFib frequently recurs without additional treatment
• Antiarrhythmic medications: Flecainide, propafenone, amiodarone, sotalol, and dofetilide can maintain normal rhythm. Each has specific indications and side effect profiles
• Catheter ablation: A procedure in which a cardiologist uses radiofrequency energy or cryotherapy to destroy the tissue triggering AFib (typically around the pulmonary veins). Success rates are highest for paroxysmal AFib and in younger patients with fewer comorbidities

Several lifestyle changes can reduce AFib burden and improve outcomes:

• Weight loss: Even modest weight reduction (10% of body weight) significantly reduces AFib recurrence
• Treating sleep apnea: Untreated sleep apnea dramatically worsens AFib. CPAP therapy reduces recurrence
• Limiting alcohol: Even moderate alcohol consumption increases AFib risk. Reducing or eliminating alcohol can meaningfully reduce episode frequency
• Blood pressure control: Hypertension is the most common modifiable risk factor — keeping it well-controlled is essential
• Regular aerobic exercise: Improves cardiovascular fitness and reduces AFib burden, though very high-intensity endurance training (marathon running, triathlons) paradoxically increases risk in some individuals

While cardiologists and electrophysiologists manage complex AFib cases, primary care plays a central role:

• Screening: EKGs at routine visits, especially in patients over 65 or with risk factors
• Risk factor management: Controlling blood pressure, diabetes, weight, and sleep apnea
• Medication management: Prescribing and monitoring anticoagulants and rate-control medications
• Coordination of care: Referring to cardiology when rhythm control procedures are needed, then managing the patient's overall health long-term
• Patient education: Helping patients understand their stroke risk, medication importance, and when to seek emergency care

Call 911 or go to the emergency room immediately if you experience:

• Sudden severe chest pain
• Difficulty breathing at rest
• Fainting or near-fainting
• Sudden weakness, numbness, or difficulty speaking (signs of stroke)
• A very rapid heart rate (above 150 beats per minute) that does not slow down

If you have been diagnosed with AFib, or if you are experiencing palpitations, unexplained fatigue, or shortness of breath, we are here to help. At Manatee Primary Care, we provide thorough cardiovascular risk assessment, EKG testing, and coordinated management of AFib and its underlying causes.

Call us at (941) 867-9362 or request an appointment online. We serve patients throughout Bradenton, Sarasota, Parrish, Anna Maria Island, Palmetto, and Ellenton.