Our locations are open for all appointments and procedures, including COVID-19 testing. Schedule an appointment online or call your doctor’s office. Patients may now be accompanied by visitors. Read our updated visitor policy.

Skip to main content

Diagnosing Atrial Fibrillation & Atrial Flutter in Adults

The heart is your body’s engine, pumping blood through your arteries and veins and supplying oxygen to your brain and other vital organs. The heart’s electrical system controls the rate and rhythm of the heartbeat by sending signals that cause the heart to contract and pump blood.

If your heart is beating normally, it falls into a steady rhythm of 60 to 80 beats per minute in a consistent, coordinated rhythm, speeding up or slowing down in response to physical activity, strong emotions, or stress. With moderate exercise, the heart typically beats 90 to 115 times per minute.

Various medical conditions can disrupt these patterns, causing the heart to beat too slowly, too quickly, or in an uncoordinated manner. These irregular heartbeats are called arrhythmias.

VIDEO: Catherine, 31, came to the Heart Rhythm Center for catheter ablation treatment to correct her abnormal heart rhythms.

Cardiac electrophysiologists at NYU Langone’s Heart Rhythm Center treat people with atrial fibrillation, or “AFib,” and atrial flutter, both of which are types of supraventricular arrhythmias that originate in the atria, or upper chambers of the heart. In atrial fibrillation and atrial flutter, the heart beats too quickly. In atrial fibrillation, it also beats erratically.

Atrial Fibrillation

Atrial fibrillation is an arrhythmia that causes the atria to beat chaotically and too fast—as quickly as 600 beats per minute. It is the most common sustained type of arrhythmia, affecting an estimated 2.7 million people in the United States. It occurs in more men than women, and it is most common in older people.

Left untreated, atrial fibrillation increases the risk of serious heart conditions. In fact, people with the condition are four to six times more likely to have a stroke.

In atrial fibrillation, the heart’s electrical system, which controls the heartbeat, misfires, causing varying amounts of blood to be pumped through the heart to the body. As a result, the atria fibrillate, or rapidly twitch and quiver, which can feel like your heart is flip-flopping in your chest.

When the irregular heartbeat associated with atrial fibrillation occurs intermittently, it’s called paroxysmal atrial fibrillation. If it occurs all the time, it’s known as persistent atrial fibrillation.

This heart rhythm disorder can prevent blood from being completely pumped into the heart’s ventricles, or lower chambers. This can cause blood to pool and, sometimes, form clots. If a clot dislodges, it can travel to the brain, causing a blockage in a blood vessel that can lead to a life threatening stroke.

AFib can cause the ventricles to beat faster, preventing them from pumping enough blood to the body. This can lead to heart failure, a serious condition in which the body doesn’t get enough blood to function properly.

Atrial Flutter

Atrial flutter is a type of arrhythmia that causes a fast but regular heartbeat—sometimes as rapid as 350 beats per minute. It’s different from atrial fibrillation, because the heart rhythm in atrial flutter is regular, not chaotic. It is the second most common tachyarrhythmia, or fast heart rhythm disorder. Often, atrial flutter and atrial fibrillation occur at the same time.

Atrial flutter occurs when electrical signals that move through the atrioventricular node, which controls the time the atria have to contract and pump blood to the lower chambers, or ventricles, slow down. This allows only a portion of the electrical signals to reach the ventricles of the heart.

The condition can be temporary or ongoing. It increases the risk of developing blood clots and stroke, because blood that isn’t pumped to the ventricles pools in the heart’s atrium.

Risk Factors

You’re at greater risk of developing atrial fibrillation or atrial flutter if you have certain underlying conditions, such as high blood pressure, coronary artery disease, cardiomyopathy and heart failure, heart valve disease, a heart infection called endocarditis, congenital heart disease, diabetes, hypothyroidism or hyperthyroidism, sleep apnea, asthma, a previous atrial fibrillation, or lung disease, such as COPD or emphysema. Prior heart attack and a family history of heart rhythm disorders also increase your risk.

Other risk factors for developing these types of arrhythmias include smoking, drinking excessive amounts of alcohol, stress, and using stimulants, including caffeine.

Signs and Symptoms

Some people with atrial fibrillation or atrial flutter have no symptoms. Any symptoms can range from mild to severe, depending on the heart’s ability to function and your overall health.

People with atrial fibrillation can have heart palpitations, an irregular or rapid heartbeat that feels like a racing or fluttering sensation in the chest; a pounding feeling in the chest; lightheadedness, dizziness, and fainting; sweating, fatigue, and weakness; chest pain or pressure; and shortness of breath.

A common sign of atrial fibrillation is exercise intolerance, meaning you tire easily while exercising and experience pain or extreme fatigue afterward. This is because the heart isn’t supplying enough oxygen-rich blood to your organs.

Symptoms of atrial flutter are similar to those associated with atrial fibrillation. They include a fluttering feeling in the chest, heart palpitations, shortness of breath, lightheadedness and dizziness, fatigue, and exercise intolerance.

A person can have both conditions at the same time.

To diagnose an arrhythmia, your NYU Langone heart specialist performs a physical exam and electrocardiogram, measures your heart rate and blood pressure, and takes a family history to determine if any relatives have heart conditions that can increase your risk for atrial fibrillation and atrial flutter. Depending on the results, your cardiac electrophysiologist may recommend additional laboratory tests, imaging tests, and noninvasive monitoring.

NYU Langone’s Heart Rhythm Center has a wide range of advanced, noninvasive cardiac imaging, remote monitoring, and electrophysiological testing equipment designed to help our experts diagnose arrhythmias and look for the underlying conditions that may be causing them.


An electrocardiogram, which is also called an EKG, records the heart’s activity by measuring electrical currents in the heart muscle. It can help determine what type of arrhythmia you have.

During the test, small, painless electrodes are placed on your chest, wrist, and ankles. They transmit information about your heart’s electrical activity to a computer, which prints a graph that indicates whether your heart is beating normally.


An echocardiogram is an ultrasound test that uses high frequency sound waves to produce detailed images of the heart, allowing a noninvasive cardiologist—a specialist who focuses on tests that are performed outside the body—to examine the heart’s size, shape, and motion as it pumps blood.

This test can also help your cardiologist to discover any blood clots, which can lead to stroke, and evaluate the heart’s ability to pump blood, called its ejection fraction. A low ejection fraction may be a sign of heart failure.

During an echocardiogram, a handheld device called a transducer is placed on your chest to send images of your heart to an integrated network of computers in our catheter laboratories.

Transesophageal Echocardiogram

In a transesophageal echocardiogram, an ultrasound probe is inserted through the mouth and into the esophagus. Because the probe is placed close to the heart, the test can provide clearer pictures of the atria than a traditional echocardiogram. Before the test, you are given a sedative.

This test is necessary to rule out the presence of blood clots in the left atrial appendage or heart chambers.

Chest X-rays

A chest X-ray uses electromagnetic waves to form images of the heart and chest. It may reveal structural problems or an injury in the heart that can lead to an arrhythmia.

MRI Scans

An MRI scan uses a magnetic field and radio waves to produce computerized, three-dimensional pictures of the heart.

This test helps the doctor assess the organ’s structure and how well its valves are pumping blood. An MRI scan can help identify whether heart tissue is scarred, which occurs with some types of cardiomyopathy, a condition that can lead to heart failure.

CT Scans

A CT scan uses X-rays to send three-dimensional, cross-sectional images of the body to a computer. Your cardiologist may use this test to help create a map of the heart that is used during a minimally invasive procedure called catheter ablation.

A chest CT scan typically takes 30 to 45 minutes. You may feel a warm sensation throughout your body if you were given an injection of contrast dye to highlight blood vessels on a computer screen.

Exercise Stress Test

Exercise can trigger a rapid heart rate, so your cardiologist may perform an exercise EKG. In this test, electrodes are attached to your chest to measure your heart rate while you walk on a treadmill, typically for up to six minutes.

Advanced Cardiac Ambulatory Telemetry

These EKG tests record the heart rhythm over a period of time, from 24 hours up to 2 weeks. They can help detect any changes in heart rhythm that may not be revealed during an EKG. You conduct your normal daily activities while wearing these devices, which are removed for showering or bathing.

Holter Monitor

This small, portable device the size of a smartphone records changes in heart rhythm over a 24-hour period.

During the test, you go about your usual daily activities, except for showering or bathing, while wearing the monitor, which is slung over your neck or attached to your belt or pants as it records your heart rhythm. The monitor connects to sticky electrodes on your chest.

Your cardiologist asks you to keep a diary of your activities while you wear the monitor, recording symptoms such as heart palpitations or chest pain. The next day, you return to NYU Langone, so your doctor can determine whether there is evidence of a heart rhythm disorder.

Ambulatory Telemetry and Remote Monitoring

If your symptoms are infrequent or unpredictable, your cardiologist may suggest you wear this lightweight, portable heart monitor for up to two weeks to measure your heart’s electrical activity.

As with the Holter monitor, the electrodes are attached to your chest to record your heart rate through a wireless device the size of a smartphone. This device sends the data to your doctor via a secure Internet site.

When you notice a symptom, such as shortness of breath or chest pain, you press a button on the device, which records the data. Some devices automatically record irregular rhythms. This information is automatically and wirelessly reported to your doctor for review on a secure website.

Implantable Cardiac Loop Recorder

Because some arrhythmias can occur intermittently, your cardiologist may recommend an implantable cardiac loop recorder, a small device that’s surgically inserted under the skin of the chest to continuously monitor and record your heart rhythm. These monitors can help doctors identify underlying heart conditions.

The device, which is the size of a computer flash drive, is surgically inserted beneath the skin of the upper chest, where it records the heart’s electrical activity. It works automatically or via a hand-held device. After an arrhythmia is diagnosed—or when the device is no longer needed—it is surgically removed.

The battery typically lasts for three years of continuous monitoring.

The Heart Rhythm Center and the Stroke Center have launched a stroke prevention partnership with the Ronald O. Perelman Department of Emergency Medicine and NYU Langone neurologists to identify people who are at-risk and monitor them for atrial fibrillation. Using a new, insertable cardiac monitor called Reveal LINQ™, the smallest implantable cardiac monitor available today, our electrophysiologists can track people with transient ischemic attack 24 hours a day, for as long as necessary to detect an arrhythmia. The device can remain implanted for up to three years.

Genetic Testing

Because your risk of some types of arrhythmias increases if a family member has such a condition, your cardiologist may recommend genetic testing through NYU Langone’s Cardiovascular Genetics Program. Our experts may recommend blood tests that identify certain changes or mutations in genes, in combination with an EKG, a stress test, and advanced telemetry, to help diagnose a genetic heart rhythm disorder.

Electrophysiological Test

During this test, your cardiac electrophysiologist studies the heart’s electrical system to detect any irregularities in heart rhythm using electrode catheters, thin, flexible wires with electrodes at the tip. The catheters are used to send electrical signals to the heart, allowing your doctor to see how the heart reacts to the signals.

In this procedure, which is performed with sedation and local anesthesia, the cardiac electrophysiologist makes an incision in the groin or neck and guides several catheters to the heart through a vein or artery. To guide the catheters, your electrophysiologist uses an imaging technique that uses X-rays, called fluoroscopy, which provides real-time images of the heart.

The cardiac electrophysiologist then sends electrical pulses through the catheters to trigger an abnormal heart rhythm. He or she analyzes the results on a computer to help identify the source of the arrhythmia.

An electrophysiology study takes one to two hours to complete, and most people go home the same day. It is typically performed at the same time as a minimally invasive procedure called catheter ablation.

Our Research and Education in Atrial Fibrillation and Atrial Flutter in Adults

Learn more about our research and professional education opportunities.