Atrial flutter is a type of abnormal heart rhythm where the upper chambers of the heart beat too fast, typically around 250 to 350 beats per minute, but in a regular, organized pattern. The lower chambers can’t keep up with that speed, so they beat at a fraction of the rate, often resulting in a pulse you can feel of around 150 beats per minute. Some people experience noticeable symptoms like a racing heart or dizziness, while others have no idea anything is wrong until it shows up on a routine test.
How Atrial Flutter Works
In a healthy heart, an electrical signal starts in a small area of the right upper chamber and travels in an orderly path through the heart muscle, triggering each beat. In atrial flutter, that signal gets trapped in a loop. Instead of firing once and resetting, the electrical impulse circles around and around the right upper chamber, creating a self-sustaining circuit. Each lap around that loop triggers a rapid contraction of the upper chambers.
The most common form, called typical atrial flutter, involves a loop that circles through a narrow strip of tissue in the lower part of the right upper chamber. This particular location matters because it’s the target when doctors treat flutter with a catheter procedure. Atypical forms can involve loops in other locations, including the left upper chamber, and are generally harder to treat.
Your heart has a built-in gatekeeper between the upper and lower chambers that prevents every one of those rapid signals from reaching the pumping chambers below. This is why your actual pulse is much slower than the 250 to 350 beats per minute happening up top. The lower chambers typically receive every second, third, or fourth signal, which is why a resting heart rate during flutter often lands around 150 (every second beat gets through) or 100 (every third beat).
What It Feels Like
The most commonly reported symptoms are palpitations (a pounding, racing, or fluttering sensation in the chest), lightheadedness, fatigue, and shortness of breath. These tend to be worse when the lower chambers are beating faster. Some people also notice they can’t exercise the way they used to, feeling winded or weak during activities that were previously easy.
Other possible symptoms include dizziness, confusion, sweating, fainting, and chest pressure. But atrial flutter can also be completely silent. Some people live with it for weeks or months without any obvious signs, especially if the heart rate stays only mildly elevated. It’s not uncommon for flutter to be discovered incidentally during a doctor’s visit or a heart monitor worn for an unrelated reason.
How It Differs From Atrial Fibrillation
Atrial flutter and atrial fibrillation (AFib) are close relatives, and they sometimes coexist in the same person, but they behave differently. In flutter, the electrical loop is organized and repetitive, so the upper chambers beat fast but in a regular rhythm. In AFib, the electrical activity is chaotic, with no single organized circuit. The upper chambers quiver erratically instead of contracting in a coordinated way, and the resulting pulse is irregularly irregular, meaning there’s no predictable pattern to the beats.
On an electrocardiogram (ECG), flutter produces a distinctive “sawtooth” pattern: a gradual downward slope followed by a sharp, steep drop and then a rapid upward stroke, repeating without any flat baseline between waves. AFib, by contrast, shows a disorganized, squiggly baseline with no repeating pattern. This visual difference makes flutter relatively straightforward to identify on a heart tracing.
Both conditions carry a risk of blood clots forming in the upper chambers, and both are managed with similar strategies. In fact, many people with atrial flutter eventually develop AFib as well, which is one reason doctors continue to monitor patients even after flutter is successfully treated.
Causes and Risk Factors
Atrial flutter shares most of its risk factors with AFib. The most common underlying contributors include high blood pressure, heart failure, valve disease, and coronary artery disease. Lung conditions like chronic obstructive pulmonary disease (COPD) can also set the stage for flutter by putting strain on the right side of the heart.
Beyond heart and lung disease, other triggers include thyroid disorders (particularly an overactive thyroid), obesity, heavy alcohol use, and recent heart or chest surgery. Age is a significant factor as well. The electrical system of the heart changes over time, and flutter becomes more common in people over 50. Some cases occur in people with no obvious underlying condition, though this is less typical.
Stroke Risk and Blood Thinners
Like AFib, atrial flutter increases the risk of stroke. When the upper chambers beat abnormally, blood can pool and form clots, which can travel to the brain. Research published in JAMA Network Open found that people with atrial flutter experienced ischemic strokes at a rate of about 1.45 per 100 people per year. The risk climbs with additional factors like age, diabetes, high blood pressure, prior stroke, and heart failure.
Doctors use a scoring system (CHA2DS2-VASc) that adds up these risk factors to estimate how likely a stroke is. For people with flutter, the stroke risk becomes significantly elevated at higher scores (5 or above on a 0 to 9 scale). Based on that score, many patients are prescribed blood thinners to reduce clot formation. Current guidelines from the American Heart Association recommend continuing blood thinners based on overall clot risk, even after flutter is treated, because AFib may develop later.
Treatment Options
Treatment for atrial flutter falls into two broad strategies: controlling the heart rate or restoring a normal rhythm.
Rate control focuses on slowing down how many signals reach the lower chambers, bringing the pulse to a more comfortable range. This is typically done with medications like beta-blockers or calcium channel blockers. Rate control doesn’t fix the flutter itself, but it reduces symptoms and protects the heart from the strain of beating too fast for too long.
Rhythm control aims to stop the flutter entirely and restore the heart’s normal electrical pattern. This can involve specialized medications, electrical cardioversion (a brief, controlled shock delivered to reset the heart’s rhythm), or catheter ablation. For many people with typical atrial flutter, ablation has become the preferred approach.
What Ablation Involves
Catheter ablation for typical atrial flutter is one of the most effective treatments in cardiac electrophysiology. A thin, flexible tube is threaded through a blood vessel (usually in the groin) up to the heart. Once positioned, it delivers targeted energy to the narrow strip of tissue that sustains the electrical loop, creating a small line of scar tissue that permanently interrupts the circuit.
The procedure has a success rate of 90% or higher for typical atrial flutter, with recurrence in only about 4% to 6% of patients. Because of these numbers, current cardiology guidelines support ablation as a first-line treatment rather than something reserved for cases where medications have failed. Success rates are lower for atypical flutter, where the circuit follows a less predictable path.
Recovery After Ablation
Recovery is relatively quick. Most people are walking the same evening and can return to desk work within two to three days. Driving is off limits for at least 48 hours. For the first week, you’ll need to avoid exercise, heavy lifting (anything over 10 pounds), and strenuous activity to let the catheter insertion site heal. A typical full recovery takes about one week, though people with physically demanding jobs may need a bit longer.
After the procedure, watch for signs that warrant a call to your doctor: bleeding or severe bruising at the insertion site, chest pain, shortness of breath, fever above 100°F, or any sudden neurological symptoms like confusion, difficulty speaking, or numbness on one side of the body.
Long-Term Outlook
For people who undergo successful ablation, the prognosis is generally excellent. The flutter circuit is permanently interrupted in the vast majority of cases, and symptoms resolve. The main caveat is that atrial fibrillation can develop independently, even after flutter is gone. This is why ongoing monitoring and, in many cases, continued blood thinners remain part of the plan.
For those managed with medications rather than ablation, flutter can often be controlled well, though it may require periodic adjustments. Left untreated, a persistently fast heart rate from flutter can weaken the heart muscle over time, a condition called tachycardia-induced cardiomyopathy. This is reversible once the rate or rhythm is brought under control, which is one of the strongest arguments for not ignoring the condition even when symptoms seem mild.