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Afib vs. Atrial Flutter vs. SVT: How to tell the difference
Afib, atrial flutter, and supraventricular tachycardia (SVT) are heart rhythm conditions that can cause similar symptoms, including a racing heartbeat, fluttering, dizziness, shortness of breath, or wearable device alerts. Because symptoms alone usually cannot tell which rhythm problem you have, getting the right diagnosis is an important first step toward the right treatment.
Afib, atrial flutter, and SVT: Key differences, symptoms, diagnosis, and treatment
Atrial fibrillation (Afib), atrial flutter, and supraventricular tachycardia (SVT) are common heart rhythm disorders that can all cause a fast or racing heartbeat.
Afib typically causes an irregular heartbeat, while atrial flutter and SVT often produce a more regular, organized rhythm.
Although these conditions can cause similar symptoms, including palpitations, dizziness, and shortness of breath, they have different underlying causes and risks.
Accurate diagnosis is important because Afib, atrial flutter, and SVT may require different tests, monitoring strategies, and treatments.
Treatment options vary by diagnosis and may include lifestyle changes, medications, or procedures.
A racing heartbeat can feel alarming, especially when it comes with dizziness, shortness of breath, chest discomfort, fatigue, or an alert from a smartwatch or wearable device.
Atrial fibrillation (or Afib), atrial flutter, and supraventricular tachycardia (also called SVT) are three heart rhythm conditions that can cause those symptoms. While they are not the same condition, they often feel comparable.
“They are all arrhythmias that originate in the upper chambers of the heart,” says Hina Amin, MBBS, a cardiac electrophysiologist with UI Health Care. “The reason they feel similar is because these arrhythmias are fast, and they tend to cause a faster heartbeat, which is over 100 beats per minute.”
Why these heart rhythm conditions can feel similar
Because all three can make the heart beat quickly, symptoms alone usually cannot confirm which rhythm problem you may have. Testing matters because each condition may carry different risks and treatment options.
For many patients, the faster rhythm is what they notice first. In addition to a racing heartbeat, other symptoms may include:
- Fluttering or pounding in the chest
- Shortness of breath
- Anxiety
- Chest pain
- Lightheadedness
- Dizziness
- Fatigue
- Irregular rhythm or high heart rate alerts from a wearable device
How you feel can depend on several factors, including how fast the heartbeat is, your age, and whether you already have heart disease.
“Some patients feel absolutely nothing, but a majority of patients will feel these sensations, and the sensation largely comes because the heart rate is elevated,” Amin says.
That is why two people with different rhythm problems may describe similar symptoms. It is also why symptoms should be checked.
How Afib, atrial flutter, and SVT are different
Even though Afib, atrial flutter, and SVT can feel similar, they are very different rhythm problems.
“Atrial fibrillation tends to be irregular, while atrial flutter and supraventricular tachycardia tend to be regular,” Amin says.
A simple way to understand the difference:
- Afib: Usually fast and irregular. It is often associated with aging, high blood pressure, diabetes, obesity, sleep apnea, alcohol use thyroid problems, or structural heart disease.
- Atrial flutter: Usually fast and regular. It can happen on its own or along with Afib and often has similar risk factors.
- SVT: Usually fast and regular. It is often seen in people with otherwise structurally normal hearts. SVT can be triggered with exercise, stress, or caffeine.
Amin says Afib is often a long-term condition.
“Typically, when we see this arrhythmia, it's a lifelong problem which can be controlled but not completely cured,” she says.
Atrial flutter can also become a problem if it is not treated, especially if it causes the heart to beat too fast for too long.
“It can cause weakness of the heart muscle, dilation of the heart muscle, enlargement, and thus cause problems, like heart failure, for the patient,” Amin says.
SVT, on the other hand, is often more manageable and may be curable with treatment.
“When it comes to SVT, these tend to be benign arrhythmias,” Amin says.
For patients, the takeaway is simple: The symptoms may overlap, but the diagnosis changes what the rhythm means and what treatment may be recommended.
"The right diagnosis matters because the management of care may be quite different, which means the prognosis may be quite different for the patient."
Hina Amin, MBBS
Why the right diagnosis matters
Getting the right diagnosis matters because Afib, atrial flutter, and SVT may carry different risks and may be treated differently
“Atrial fibrillation as an arrhythmia is associated with the risk of stroke, and this risk of stroke is not there with the other arrhythmias,” Amin says.
For Afib, care often focuses on reducing the amount of time a patient spends in the irregular rhythm, controlling symptoms, lowering stroke risk, and managing long-term risk factors.
“Atrial fibrillation management tends to control the arrhythmia burden, and patients may need some lifelong follow-up and management to control it,” Amin says.
For SVT, treatment may be more straightforward.
“Ablation can be curative in a majority of these patients,” she says.
Patients should not rely on symptoms alone to decide what they have. A correct diagnosis helps the care team choose the safest and most effective next step.
“The right diagnosis matters because the management of care may be quite different, which means the prognosis may be quite different for the patient," Amin says.
How heart rhythm problems are diagnosed
Symptoms can raise concern for a rhythm problem, but testing is always required.
An electrocardiogram, or EKG, is usually the first test used to identify the rhythm. This is a quick test that records the heart’s electrical activity.
“It can differentiate these arrhythmias from each other,” Amin says.
But some arrhythmias come and go. If the rhythm is not happening during an office visit or emergency room visit, a patient may need longer monitoring.
In addition to EKGs, tests may include:
- Holter monitor: A wearable patch or monitor that records heart rhythm over hours or days.
- Loop recorder: A small, implanted device that can monitor rhythm over a longer period of time.
- Echocardiogram: An ultrasound that looks at the structure and function of the heart.
- Stress test: A test that may be used to evaluate how blood flows to the heart during activity or medication-induced stress.
Amin says wearable devices can also be helpful, but they are not perfect.
“The watches and other devices tend to have a margin of error,” she explains, noting that sometimes they can indicate that you have an arrhythmia when you do not.
“That's why it's important to verify that with a provider,” Amin says.
If a wearable device shows an irregular rhythm, high heart rate, or possible Afib alert, contact your provider. If symptoms are severe, you may need emergency care.
“If you are feeling sick, and then your watch is giving you an alert, reaching out to your provider may not be enough,” Amin says. “You may need to go to the emergency room or call 911.
Heart rhythm symptoms?
A racing heartbeat, fluttering, dizziness, shortness of breath, or wearable device alert may need testing to confirm the cause. Our heart rhythm specialists can help diagnose the problem and explain your treatment options.
Ablation procedures can be highly effective for atrial flutter and supraventricular tachycardia, with success rates often falling in the 90% to 100% range.
How an electrophysiologist can help
A cardiac electrophysiologist is a heart rhythm specialist.
Electrophysiologists diagnose and treat arrhythmias, including Afib, atrial flutter, and SVT.
If a fast or irregular heartbeat keeps occurring, an electrophysiologist can help confirm the rhythm and explain which treatment options fit the diagnosis.
Treatment may include medication, catheter ablation, or both, depending on the diagnosis, symptoms, risk factors, and overall heart health.
Some medications slow the heart rate. Others help prevent an irregular rhythm from happening. Ablation is a procedure that targets the source of the abnormal rhythm. It is done under sedation or general anesthesia and is usually an outpatient procedure.
Ablation may be especially effective for atrial flutter and SVT.
“They tend to be more curative — in the 90% to 100% range — for atrial flutter and supraventricular tachycardia,” Amin says.
For Afib, lifestyle changes may also be part of long-term care.
“There are various things in a patient's lifestyle that can be altered, like smoking cessation, alcohol cessation, sleep apnea, blood pressure management, weight loss, and exercise,” Amin says.
If symptoms are frequent and recurring, disruptive, or paired with wearable alerts, scheduling with a heart rhythm specialist can help you get the right diagnosis and understand their next steps.
Knowing the difference between Afib, atrial flutter, and SVT
These heart rhythm problems can cause similar symptoms, but they may carry different risks and treatment options.
| Afib | Atrial Flutter | SVT | |
|---|---|---|---|
Heart rhythm | Rapid, irregular (chaotic) | Rapid, regular | Rapid, regular |
Common symptoms | Racing heartbeat, fluttering, shortness of breath, dizziness, fatigue | Racing heartbeat, fluttering, shortness of breath, dizziness, fatigue | Sudden racing heartbeat, fluttering, dizziness, shortness of breath, anxiety-like symptoms |
Stroke risk | High, can increase stroke risk | Medium, may increase stroke risk, especially when linked with Afib or other risk factor | None, not usually linked to the same stroke risk as Afib |
Common causes or risk factors | Age, high blood pressure, diabetes, obesity, sleep apnea, alcohol use, thyroid conditions, heart disease | Similar to Afib; may occur with Afib
| Can happen in people with otherwise normal hearts |
Treatment options | Medication, lifestyle changes, stroke prevention, cardioversion, ablation | Medication, cardioversion, ablation
| Medication, monitoring, ablation
|
Why diagnosis matters | May need long-term management | Untreated episodes can strain the heart, potentially curable | May be curable with ablation |
Get answers about your heart rhythm
Afib, atrial flutter, and SVT can feel similar, but the right diagnosis matters. Schedule an appointment to talk with a heart rhythm specialist.
