Atrial Flutter in Singapore: Symptoms, Causes and Treatment

Atrial flutter is a fast, organised heart rhythm in which the electrical signal races around a fixed loop in the upper chambers of the heart, usually the right atrium, making them beat around 250 to 300 times a minute. It is a type of arrhythmia (an abnormal heart rhythm) that is closely related to atrial fibrillation and often occurs in the same patients. If you have just been told you have atrial flutter, this page explains what it is, its symptoms, why it raises stroke risk, and how it is diagnosed and treated – including an ablation procedure that is often curative. It is general information and not a substitute for advice from your own doctor.

What Is Atrial Flutter?

In a normal heartbeat, each electrical signal travels once through the heart and stops. In atrial flutter, the signal instead becomes trapped in a self-sustaining loop – a re-entry circuit – and circles continuously. The most common form, called typical atrial flutter, uses a well-defined circuit in the right atrium that passes through a strip of tissue called the cavotricuspid isthmus. Because the circuit is so regular, the atria contract in a rapid, even pattern that produces a distinctive “sawtooth” pattern on the ECG.

The upper chambers may fire around 300 times a minute, but the atrioventricular node (the heart’s electrical gatekeeper) blocks most of these signals, so the ventricles – the main pumping chambers – usually beat at a fraction of that rate, commonly around 150 beats per minute. Atrial flutter is a form of supraventricular tachycardia (SVT) – a fast rhythm arising above the ventricles – but it uses a distinct circuit and is managed differently from the classic short-circuit type of SVT. Atrial flutter and atrial fibrillation frequently coexist: many people flip between the two, and treating one can unmask the other.

Atrial Flutter Symptoms

Symptoms depend on how fast the ventricles are beating. They may include:

• Palpitations – a fast, pounding or fluttering heartbeat, often steady rather than irregular
• Breathlessness, at rest or on exertion
• Fatigue and reduced exercise tolerance
• Dizziness or light-headedness
• Chest tightness or discomfort
• Near-fainting or, less often, fainting

Some people have no symptoms at all, and the rhythm is picked up on a routine pulse check, a wearable device or an ECG done for another reason. Because a sustained fast rate can gradually weaken the heart muscle over weeks, even mild symptoms are worth assessing.

When to Seek Emergency Help

Call 995 if a fast heartbeat occurs together with:

• Chest pain or pressure
• Fainting or collapse
• Severe or sudden breathlessness
• Confusion, or a cold, clammy, pale appearance

A very fast rhythm that makes you feel faint is treated as an emergency until proven otherwise.

Causes and Risk Factors

Atrial flutter usually develops on a background of stretched, scarred or diseased atrial tissue. Common contributors include:

• High blood pressure – the most common underlying factor, and highly prevalent in Singapore
• Coronary artery disease and previous heart attack
• Heart valve disease and heart failure, which stretch the atria
• Chronic lung disease and obstructive sleep apnoea
• An overactive thyroid, alcohol excess, and the period after heart or lung surgery
• Increasing age, and diabetes

Atrial flutter shares nearly all of its risk factors with atrial fibrillation, which is why the two so often appear together.

How Atrial Flutter Is Diagnosed

• Electrocardiogram (ECG) – a resting electrocardiogram (ECG) is usually all that is needed to confirm the diagnosis if the rhythm is present, showing the characteristic sawtooth flutter waves.
• 24-hour Holter or patch monitor – captures the rhythm during normal life when episodes come and go, and shows how fast the heart runs over a day.
• Echocardiogram – an ultrasound scan of the heart to look for valve disease, chamber enlargement or reduced pumping strength, and to check for clots before treatment.
• Blood tests – thyroid function and other checks to find reversible drivers.

Treatment Options

Treatment has two goals: controlling the rhythm and preventing stroke.

• Stroke prevention – like atrial fibrillation, atrial flutter allows blood to pool and clot in the atria, which can travel to the brain. Anticoagulants (blood-thinning medicines) are prescribed based on your individual stroke risk, not on how often you have symptoms.
• Rate and rhythm control medication – drug classes such as beta-blockers or calcium channel blockers slow the ventricular rate; anti-arrhythmic drugs may be used to hold normal rhythm in selected cases.
• Electrical cardioversion – a brief, controlled shock under sedation that can reset the heart to normal rhythm.
• Catheter ablation – for typical atrial flutter this is often curative. Using thin catheters guided into the heart, the cardiologist places a line of small burns or freezes across the cavotricuspid isthmus, breaking the circuit so the signal can no longer loop. Cavotricuspid isthmus ablation has a high success rate for typical flutter and is frequently offered as a first-line definitive treatment rather than lifelong medication. It is often planned alongside an electrophysiological (EP) study, which maps the circuit from inside the heart.

Because flutter and fibrillation coexist, some people still develop atrial fibrillation after a successful flutter ablation and continue anticoagulation and monitoring.

When to See a Cardiologist

See a cardiologist if you have palpitations, an unexplained fast or irregular pulse, breathlessness or dizziness, or if a wearable device has flagged an abnormal rhythm. Because atrial flutter carries a stroke risk and is often curable with a single procedure, early specialist assessment matters. Our team managing heart rhythm disorders can confirm the diagnosis and discuss whether ablation is suitable for you.

Frequently Asked Questions

Is atrial flutter serious?

It is usually not immediately life-threatening, but it should not be ignored. A sustained fast rate can weaken the heart over time, and flutter carries a stroke risk similar to atrial fibrillation. The good news is that typical atrial flutter is often curable with ablation.

What is the difference between atrial flutter and atrial fibrillation?

Both start in the upper chambers, but flutter is an organised loop that produces a regular, sawtooth pattern, while fibrillation is chaotic and irregular. They share the same risk factors and often occur in the same person, and both raise stroke risk.

Can atrial flutter be cured?

Typical atrial flutter can often be cured by catheter ablation of the cavotricuspid isthmus, which breaks the electrical circuit. Success rates are high, though some people later develop atrial fibrillation and need ongoing monitoring.

Does atrial flutter cause a stroke?

It can. The rapid, ineffective contraction of the atria lets blood pool and form clots that may travel to the brain. This is why anticoagulant medication is prescribed based on your overall stroke risk, regardless of how often you feel symptoms.

Can you live a normal life with atrial flutter?

Most people can, especially once the rhythm is controlled or cured and stroke risk is managed. Treating underlying factors such as high blood pressure, sleep apnoea and thyroid problems helps keep it from returning.