How Dangerous Is Atrial Fibrillation? Risks, Complications, and When to Seek Care

How Dangerous Is Atrial Fibrillation? Risks, Complications, and When to Seek Care

Atrial fibrillation (AF), or “AFib” for short, is the most common type of heart rhythm disorder, affecting millions of adults in the United States and around the globe. Although some people with AF experience mild or no symptoms, atrial fibrillation can significantly increase the risk of serious complications, including stroke, heart failure, and long-term cardiovascular damage.

Understanding how dangerous atrial fibrillation can be—and when to seek medical care—can help patients protect their heart health and prevent life-threatening complications.

What Is Atrial Fibrillation?

Atrial fibrillation is an abnormal heart rhythm that occurs when the upper chambers of the heart (atria) beat irregularly and out of coordination with the lower chambers (ventricles). Instead of a normal, steady heartbeat, AF causes a rapid and chaotic heart rhythm that may reduce the heart’s efficiency.

When the heart beats irregularly, blood may pool in the atria, increasing the risk of blood clot formation. These clots can travel to the brain and cause stroke.

How Dangerous Is Atrial Fibrillation?

While AF is not always immediately life-threatening, it can lead to serious health complications if left untreated. The severity of AF depends on several factors, including underlying heart disease, frequency of episodes, and overall cardiovascular health.

Increased stroke risk

One of the most serious complications of atrial fibrillation is stroke. AF significantly increases the likelihood of blood clot formation in the heart, which can travel to the brain and block blood flow.

Patients with AF have a stroke risk that is several times higher than individuals with normal heart rhythm. Stroke caused by AF is often more severe and disabling.

Heart Failure

Over time, untreated atrial fibrillation can weaken the heart muscle and lead to heart failure. Rapid or irregular heart rhythms force the heart to work harder, reducing its ability to pump blood efficiently.

Symptoms of heart failure may include:

  • Shortness of breath
  • Fatigue
  • Fluid retention and swelling

  • Reduced exercise tolerance

Increased Risk of Other Cardiovascular Complications

Atrial fibrillation may also increase the risk of:

  • Cardiomyopathy
  • Chronic fatigue
  • Reduced quality of life
  • Hospitalization for heart-related conditions 

Symptoms of Atrial Fibrillation

Some individuals with AFib experience noticeable symptoms, while others may not realize they have the condition until complications occur.

Common symptoms include:

  • Rapid or irregular heartbeat
  • Heart palpitations
  • Chest discomfort
  • Shortness of breath
  • Fatigue or weakness
  • Dizziness and lightheadedness
  • Reduced exercise tolerance

Because AF can occur intermittently, symptoms may come and go, making diagnosis and treatment more challenging.

Who Is at Higher Risk of Atrial Fibrillation?

Several medical conditions and lifestyle factors increase AF risk, including:

  • High blood pressure
  • Coronary artery disease
  • Heart valve disease
  • Congestive heart failure
  • Diabetes
  • Obesity
  • Sleep apnea
  • Smoking
  • Excessive alcohol consumption
  • Family history of arrhythmias

Age is also a major risk factor, with AF becoming more common in adults over age 60.

When Should You Seek Medical Care?

Early diagnosis and treatment of atrial fibrillation can significantly reduce the risk of stroke and heart failure.

Patients should schedule evaluation with a cardiologist if they experience:

  • Irregular or rapid heartbeat
  • Unexplained fatigue
  • Shortness of breath
  • Dizziness or fainting
  • Chest discomfort

Seek Emergency Medical Care Immediately If You Experience:

  • Severe chest pain
  • Sudden weakness or numbness
  • Difficulty speaking or understanding speech
  • Sudden vision problems
  • Loss of balance or coordination

These may be signs of stroke or heart attack and require immediate treatment.

Treatment Options for Atrial Fibrillation

AF treatment focuses on controlling heart rhythm, preventing blood clots, and reducing cardiovascular risk.

Medications

Patients may be prescribed medications to:

  • Control heart rate
  • Restore normal heart rhythm
  • Prevent blood clot formation
  • Manage underlying cardiovascular conditions

Cardioversion

Cardioversion uses electrical or medication therapy to restore normal heart rhythm.

Catheter Ablation

Catheter ablation is a minimally invasive procedure that targets abnormal electrical signals causing AF.

Lifestyle Modifications

Lifestyle changes play a critical role in AF management and prevention.

Patients are encouraged to:

  • Maintain healthy weight
  • Control blood pressure and cholesterol
  • Exercise regularly
  • Avoid excessive alcohol
  • Stop smoking
  • Manage sleep apnea
  • Reduce stress

Atrial Fibrillation Care in Tampa, Florida

Individuals living in Tampa and surrounding communities—including South Tampa, Hyde Park, Davis Islands, Carrollwood, Westchase, Clearwater, and St. Petersburg—can benefit from specialized AF evaluation and treatment.

At Ascent Cardiology, patients receive advanced arrhythmia evaluation, heart rhythm monitoring, stroke risk assessment, and personalized AF treatment strategies designed to improve long-term cardiovascular outcomes.

Early diagnosis and preventative cardiology care can significantly reduce AFib-related complications.

Preventing AF Complications

Although atrial fibrillation cannot always be prevented, patients can reduce complications by:

  • Monitoring blood pressure regularly
  • Maintaining heart-healthy lifestyle habits
  • Taking prescribed medications consistently
  • Scheduling routine cardiology follow-up visits
  • Managing chronic medical conditions

Preventative cardiology plays an essential role in reducing AF progression and stroke risk.

Schedule an Atrial Fibrillation Evaluation

If you experience symptoms of atrial fibrillation or have cardiovascular risk factors, early cardiology evaluation is essential. Patients in Tampa Bay can scheduled a consultation with our board-certified cardiologist, Sachin Diwadkar, MD, FACC, FASE, at Ascent Cardiology for comprehensive arrhythmia screening and personalized treatment planning. Please request an appointment today. 

Medical Disclaimer

The content provided on the Ascent Cardiology website is intended for general educational and informational purposes only. The information, articles, and media presented on this website do not constitute medical advice, diagnosis, or treatment recommendations. Content published on this website is not intended to replace consultation, evaluation, or treatment by qualified healthcare professionals, including the providers at Ascent Cardiology or other licensed medical professionals.

If you believe you may be experiencing a medical emergency, call 911 or seek immediate emergency medical care.

The medical information, opinions, and educational materials presented on this website are provided for general awareness and may not reflect the specific clinical practices or medical opinions of Ascent Cardiology or its providers. Reliance on any information provided on this website is solely at your own risk.

This website may include links to third-party medical or educational websites for informational purposes only. Ascent Cardiology does not control, endorse, or assume responsibility for the accuracy, reliability, or content of any third-party websites linked from this site.

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Diseases of the Mitral Valve

The mitral valve is one of the four valves found in the human heart. It is located between the left atrium and the left ventricle. Like all heart valves, the mitral valve helps regulate the flow of blood through the heart; specifically, from the left atrium to the left ventricle. Whenever the heart contracts, the mitral valve seals itself off to stop blood from flowing into the lungs. A diseased or damaged mitral valve cannot function and should be surgically repaired or replaced by a cardiologist in Tampa.

Those suffering from a condition involving the mitral valve can get progressively worse over time if left untreated. Mitral valve diseases, such as mitral valve regurgitation and mitral valve stenosis, can be debilitating on their own, but they also open the door for other conditions, such as heart dilation and atrial fibrillation. If you are experiencing symptoms such as shortness of breath, chest pain, dizziness, fatigue, swollen ankles or legs, persistent coughing, or heart palpitations, consult a cardiologist in Tampa, FL, from Ascent Cardiology Group to see if you are suffering from one of the diseases of the mitral valve.
Mitral Valve Prolapse and Regurgitation
If the leaflets of the mitral valve bulge, or prolapse, it can cause issues during heart contractions, such as mitral valve regurgitation. Mitral valve regurgitation occurs when a prolapsed mitral valve allows blood to leak into the atrium from the ventricle. Although mitral valve prolapse isn’t especially harmful, and most people don’t realize that they have it, in some cases, treatment is required. This condition is most commonly caused by myxomatous valve disease, which is when the valve leaflets are too stretchy.

Approximately two percent of the population suffers from mitral valve prolapse. Generally, this disease is passed down through genetics, but it can also be caused by health problems, like connective tissue diseases. Detecting mitral valve prolapse without the assistance of a cardiologist in Tampa can be difficult. Your cardiologist can listen to your heartbeat with a stethoscope to detect a murmur that may be indicative of mitral valve prolapse. Other symptoms include heart palpitations, chest pain, and fatigue.
Mitral Valve Stenosis
Unlike mitral valve prolapse, which occurs when the valve leaflets of the mitral valve are too stretchy, mitral valve stenosis occurs when these leaflets become too thick or stiff. When this happens, the leaflets can fuse together, resulting in a narrowed valve opening that constricts blood flow from the left atrium to the left ventricle, causing fatigue, shortness of breath, swelling, and more. Individuals suffering from this condition must consult a cardiologist in Tampa, FL, to determine whether the condition has progressed to the point where surgery will be required. If your condition becomes worse, your cardiologist can repair or replace the mitral valve utilizing a minimally invasive surgical option.
To consult a cardiologist in Tampa, FL, from Ascent Cardiology Group, please request an appointment today.
Disclaimer: The contents of this website are for general educational purposes only. All content and media on the Ascent Cardiology Group website does not constitute professional medical advice nor is the information intended to replace the services of Ascent Cardiology Group or other qualified medical professionals. If you believe you are having a medical emergency, call 911 immediately.

The content, views, and opinions communicated on this website do not represent the views of Ascent Cardiology Group. Reliance on any information provided by this website is solely at your own risk. Although this website contains links to other medical websites, this is strictly for informational purposes. Ascent Cardiology Group is not responsible nor do they approve of the content featured on any third party linked websites referenced on this website.
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Athlete’s Heart: Symptoms, Causes & When to Worry

Athlete’s heart is the normal way the heart adapts to years of intense training. A well-trained athlete’s heart is often larger, beats more slowly at rest and pumps more blood with each beat. These changes are a sign of fitness, not disease.

However, some of these normal changes can look like serious heart conditions on an ECG or echocardiogram. And rarely, a dangerous heart problem can hide behind what looks like athlete’s heart. Here’s what’s normal, what causes these changes, and when an athlete should see a cardiologist.

What Is Athlete’s Heart?

Athlete’s heart, also called athletic heart syndrome, describes structural and electrical changes in the heart caused by regular, intense exercise. It’s most common in people who train many hours a week, such as competitive endurance athletes, team-sport athletes and dedicated recreational athletes.

Athlete’s heart is not a disease and doesn’t need treatment. In most cases, the changes partly reverse within a few months after an athlete reduces training.

What Causes Athlete’s Heart?

During exercise, the heart pumps up to five or more times as much blood as it does at rest. Over time, it remodels to handle that workload more efficiently. The type of training shapes how the heart adapts:

  • Endurance training (running, cycling, swimming, rowing) mainly increases the size of the heart’s chambers, so each beat moves more blood.
  • Strength training (weightlifting, wrestling, throwing sports) mainly thickens the heart’s walls to handle short bursts of high pressure.
  • Mixed sports such as basketball, hockey and soccer often produce a combination of both.

A larger, more efficient heart can move the same amount of blood with fewer beats. That’s why many athletes have a resting heart rate in the 40s or even lower.

Common Signs of Athlete’s Heart

Athlete’s heart usually causes no symptoms. It’s often noticed during a physical, a pre-participation screening or a test done for another reason. Normal findings include:

  • A slow resting heart rate (sinus bradycardia), sometimes below 50 beats per minute
  • A heart murmur caused by increased blood flow, often harmless
  • An enlarged heart on an echocardiogram or chest X-ray, with normal pumping function
  • Mildly thickened heart walls
  • ECG changes that would be unusual in non-athletes but are considered normal in trained athletes

Expert guidelines, known as the International Criteria for ECG interpretation in athletes, list ECG findings that are normal in athletes. These include a slow heart rate, mild heart block (first-degree AV block), early repolarization and high voltage suggesting a larger heart. Recognizing these patterns prevents athletes from being wrongly disqualified from sport.

What Makes the 'Athlete's Heart' So Unique? | by Brady Holmer | Sharing Science | Medium

Athlete’s Heart vs. Hypertrophic Cardiomyopathy and Other Conditions

The biggest challenge is telling athlete’s heart apart from heart conditions that can cause sudden cardiac arrest during exercise. The most important is hypertrophic cardiomyopathy (HCM), an inherited thickening of the heart muscle. We cover HCM in more detail in 5 lesser-known heart conditions.

Other conditions that can mimic or hide behind athlete’s heart include:

  • Arrhythmogenic cardiomyopathy (ARVC), in which heart muscle is replaced by scar and fat
  • Dilated cardiomyopathy, a weakened, enlarged heart
  • Myocarditis, inflammation of the heart muscle, often after a viral illness
  • Coronary artery anomalies, arteries that start or run in an abnormal location
  • Inherited rhythm disorders, such as long QT syndrome, Brugada syndrome and Wolff-Parkinson-White syndrome

In athletes over 35, coronary artery disease becomes the most common cause of exercise-related cardiac events. The ACC summarizes the causes of sudden cardiac arrest and death in athletes.

When to Worry: Warning Signs in Athletes

Athlete’s heart itself doesn’t cause symptoms. If an athlete has any of the following, they should stop training and see a cardiologist:

  • Fainting or near-fainting during or right after exercise. This is the most important red flag.
  • Chest pain or pressure with exertion
  • Shortness of breath out of proportion to the effort
  • Palpitations, a racing or irregular heartbeat, especially with dizziness
  • A sudden drop in performance or unusual fatigue without explanation
  • Symptoms after a viral illness, such as chest pain or palpitations after COVID-19 or the flu
  • A family history of sudden cardiac death before age 50, cardiomyopathy or inherited rhythm disorders
  • An abnormal ECG flagged during a screening physical

Long-term endurance athletes, especially middle-aged men, also have a higher risk of atrial fibrillation, an irregular heart rhythm. The ACC reviews what contributes to AFib in former endurance athletes. For a broader checklist of symptoms, see 10 warning signs you should see a cardiologist.

Call 911 if an athlete collapses. Start CPR and use an AED immediately. Every minute without CPR and defibrillation lowers the chance of survival.

How Doctors Diagnose Athlete’s Heart

A cardiologist experienced with athletes uses several tools to separate normal adaptation from disease:

  • 12-lead ECG, interpreted using athlete-specific criteria
  • Echocardiogram to measure wall thickness, chamber size, pumping and filling
  • Cardiac MRI to look for scarring or abnormal thickening patterns, especially in gray-zone cases
  • Cardiopulmonary exercise testing to measure fitness and check rhythm during exercise
  • Holter or event monitoring to record the heart’s rhythm over days to weeks
  • Genetic testing when an inherited condition is suspected
  • Supervised detraining, a short period of reduced exercise, followed by repeat imaging

The goal is to keep healthy athletes in their sport while protecting those with a real risk. Today, many athletes with a heart condition can continue to compete after an individualized, shared decision-making discussion with their cardiologist.

Heart Screening for Athletes

In the U.S., pre-participation physicals typically include a medical history, family history, and physical exam. Some programs, including many collegiate and professional leagues, also add an ECG and echocardiogram. Beginning in the 2026-2027 school year, under Florida’s Second Chance Act (Florida Statute 1006.20), students participating in any Florida High School Athletic Association (FHSAA)-sanctioned athletic tryout, conditioning, practice, or competition for the first time must have a cleared electrocardiogram (ECG/EKG) before they can participate.

Read the American Heart Association’s overview of screening young athletes for heart disease.

Adult and masters athletes, especially those over 35 or with risk factors such as high blood pressure, high cholesterol, diabetes or smoking, may benefit from a cardiology evaluation before starting or intensifying training.

Frequently Asked Questions

Is athlete’s heart dangerous? No. Athlete’s heart is a normal, healthy adaptation to training. The concern is making sure it isn’t hiding a different heart condition, which a cardiologist experienced with athletes can sort out.

Is a resting heart rate in the 40s normal for athletes? Yes. Trained athletes often have resting heart rates in the 40s and sometimes lower. A slow heart rate is a concern only if it comes with dizziness, fainting, fatigue or shortness of breath.

Does athlete’s heart go away? The changes usually partly reverse within a few months of reducing training. This is one way doctors distinguish athlete’s heart from conditions like hypertrophic cardiomyopathy, which don’t improve with rest.

Can you have athlete’s heart without being a professional athlete? Yes. Marathon runners, triathletes, cyclists and other dedicated recreational athletes who train many hours a week can develop athlete’s heart.

Should my child get an ECG before playing sports? It depends on your child’s history, symptoms, family history and sport. A doctor can review whether an ECG is appropriate. Any child who faints during exercise, has chest pain with exertion or has a family history of sudden cardiac death should see a cardiologist before playing.

Sports Cardiology Care in Tampa

As team cardiologist for the Tampa Bay Lightning and former team cardiologist for the Toronto Raptors, our cardiologist has evaluated elite athletes at the highest level of competition. We bring the same expertise to athletes of every age and level, from high school competitors to weekend warriors and masters athletes.

We offer athlete-specific ECG interpretation, echocardiography, exercise testing and individualized return-to-play guidance.

Request an appointment or call (813) 540-4322.

602 S Audubon Ave, Suite A, Tampa, FL 33609

Medical Disclaimer

The content provided on the Ascent Cardiology website is intended for general educational and informational purposes only. The information, articles, and media presented on this website do not constitute medical advice, diagnosis, or treatment recommendations. Content published on this website is not intended to replace consultation, evaluation, or treatment by qualified healthcare professionals, including the providers at Ascent Cardiology or other licensed medical professionals.

If you believe you may be experiencing a medical emergency, call 911 or seek immediate emergency medical care.

The medical information, opinions, and educational materials presented on this website are provided for general awareness and may not reflect the specific clinical practices or medical opinions of Ascent Cardiology or its providers. Reliance on any information provided on this website is solely at your own risk.

This website may include links to third-party medical or educational websites for informational purposes only. Ascent Cardiology does not control, endorse, or assume responsibility for the accuracy, reliability, or content of any third-party websites linked from this site.

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