Medically Reviewed By: Dr Paul Lim – MBBS, M.Med (Int Med), MRCP (UK), FAMS (Cardiology)
An irregular heartbeat — also known as a cardiac arrhythmia — is any disturbance in the normal rate or rhythm of your heartbeat. It can feel like a flutter, a skipped beat, or a racing heart, or it may not cause any noticeable symptoms at all. Some are benign; others can lead to serious complications including stroke or heart failure. If you are unsure, speak with our heart rhythm specialist for peace of mind.
Senior Consultant Cardiologist & Cardiac Electrophysiologist
Dr Paul Lim subspecialises in heart rhythm disorders, performing catheter ablation, pacemaker, and defibrillator implantation for arrhythmia patients. He completed advanced fellowship training at Barts Heart Centre, London under Singapore’s HMDP award.
An irregular heartbeat is the lay term for what doctors call a cardiac arrhythmia — any disturbance in the rate, rhythm, or sequence of the electrical signals that drive your heartbeat. It is also known as heart arrhythmia, dysrhythmia, or heart rhythm disorder. There are many different types, each with its own cause and treatment.
A healthy resting heart beats regularly between 60 and 100 times per minute (trained athletes often rest below 60 without problem). Rhythm changes fall into three broad patterns:
Symptoms can arrive suddenly. The following details help your doctor narrow the diagnosis:
Most people experience occasional palpitations that turn out to be normal heart beats that feel a little faster or stronger. Others have a true heart rhythm disorder such as atrial fibrillation, supraventricular tachycardia, or a heart block that needs specialist management. A proper diagnosis by a cardiologist should be obtained as some causes can lead to potentially serious consequences.
This is the single most common question patients ask. The honest answer is: it depends on your symptoms and overall heart health. Use the traffic-light guide below to decide what to do.
An irregular heartbeat is dangerous and needs emergency attention if you also have:
See a cardiologist promptly if your irregular heartbeat is:
These are less likely to indicate a serious arrhythmia, but see a doctor for a proper diagnosis if you are unsure:
Not sure which category you fall into? Speak to a cardiologist for a proper evaluation and peace of mind.
A normal resting heart rate is 60–100 beats per minute (BPM). A resting heart rate of 120 BPM is not normal — it falls into the tachycardia range and should be evaluated. Drag the slider below to see and feel the difference between a slow, normal, fast, and dangerously fast heartbeat.
Normal resting heart rate. Most healthy adults sit in this range at rest — this is what a healthy conduction system produces when everything is working correctly.
Worried about your heart rhythm? Get a professional assessment.
An irregular heartbeat happens when the heart’s normal electrical signals are disrupted, causing the heart to beat too fast, too slow, or in an uneven pattern. Some causes are everyday triggers like coffee, stress, or poor sleep. Others signal an underlying condition such as a heart problem, thyroid disease, sleep apnoea, or anxiety. Often more than one factor is at play.
Note: this is not an exhaustive list. If you are experiencing symptoms, consult a doctor for a proper evaluation.
Some arrhythmias appear in otherwise healthy people with no identifiable cause — especially benign premature beats. However, premature ventricular contractions (PVCs) occurring at a high burden may still warrant evaluation, as they can occasionally affect heart function over time. A one-off specialist assessment is worth doing so that you know what you are dealing with.
Arrhythmias can be silent. A significant proportion of atrial fibrillation episodes, for example, cause no symptoms at all. When symptoms do occur, they overlap with many other conditions, so an ECG is crucial to confirming the diagnosis. Because arrhythmias often come and go, ambulatory prolonged monitoring such as a Holter monitor or event recorder may be needed when the resting ECG is normal.
Talk to Dr Paul Lim for a proper diagnosis and peace of mind.
These simple checks don’t replace a clinical ECG, but they help you recognise and record symptoms between consultations.
Sit quietly for 5 minutes. Place two fingers on the thumb aspect of your wrist or on your neck just below your jaw angle. Count beats for 30 seconds and double. A regular pulse taps steadily; an irregular one skips, doubles, or arrives early.
Apple Watch, Garmin, Fitbit, and Samsung Galaxy Watch can record a single-lead (channel) ECG and help document the dates and times of your symptoms. Bring your recordings to your consultation.
Many home monitors (Omron, Braun) display a symbol when they detect an uneven pulse. If this indicator appears repeatedly, book a consultation with a cardiologist.
Record when episodes occur, their duration, what you were doing, what you ate or drank, and any other symptoms. The more information you can share, the easier it is for your specialist to interpret patterns.
Cardiac arrhythmias are grouped by where they start in the heart and how fast they beat. Each abnormal rhythm leaves a distinctive signature on an electrocardiogram (ECG) — here is how they compare to a normal heartbeat and what each one means for treatment.
Regular, evenly spaced beats at 60–100 beats per minute. Each cycle shows a P wave, QRS complex, and T wave in the correct order — the rhythm a healthy heart should produce at rest.
No visible P waves — a chaotic, wavering baseline replaces the normal flat line, and QRS complexes fall at unpredictable intervals. The most common sustained arrhythmia and a major risk factor for stroke.
Continuous “sawtooth” flutter waves replace the flat baseline, produced by a fast re-entrant circuit in the right atrium. Feels like a fast pounding heartbeat.
Fast, narrow QRS complexes arriving at a regular rapid rate — usually 150–220 beats per minute — with P waves often lost inside the preceding T wave. Covers AVNRT, AVRT and WPW syndrome, typically in younger adults.
Wide, bizarre-looking QRS complexes firing rapidly from the lower chambers — P waves and T waves are lost inside the wide beats. Sustained VT can progress to cardiac arrest.
Beats of normal shape spaced far apart — a heart rate under 60 beats per minute. Long gaps between beats can cause fatigue, dizziness, or fainting.
A P wave fires but the expected QRS fails to follow — the electrical signal from the atria is delayed or blocked at the AV junction. Higher-grade heart block causes dizziness, fainting, or dangerous pauses.
Normal beats are interrupted by an early, wide complex followed by a compensatory pause. This is the “skipped beat” or “thump” patients describe — usually benign in a structurally normal heart.
Normal-shaped beats with a slight, cyclical variation in the R-R interval — the rhythm speeds up on inspiration and slows on expiration. Common in children and young adults.
These tracings are simplified illustrations for patient education and are not a substitute for a real 12-lead ECG interpretation by a qualified doctor. If you are concerned about your heart rhythm, please book an appointment for a proper evaluation.
Because arrhythmias often come and go, the diagnostic process is a tiered approach that starts simple and escalates only if needed.
Dr Lim will ask about your symptoms, triggers, family history, medications, and lifestyle, then examine your pulse, blood pressure, and heart sounds.
A 10-second recording of the heart’s electrical activity. An ECG tracing is diagnostic if captured during symptoms, and often picks up underlying heart block or conduction abnormalities even between episodes.
Because many arrhythmias are intermittent, a 24-hour to 14-day portable ECG monitor can be used to catch them in daily life. Longer recorders that can be implanted under the skin are available for rare symptoms.
An ultrasound scan of the heart to check the structure, size, and pumping function. Detects the underlying heart conditions that cause many arrhythmias.
Thyroid function, electrolytes (potassium, magnesium), full blood count, and cardiac markers where indicated.
A specialist minimally invasive test used to clinch the diagnosis of the arrhythmia when ablation is the intended treatment. Catheters measure electrical activity directly inside the heart to pinpoint the source of the arrhythmia.
The best treatment depends on the type, cause, symptoms, and your individual risk. Most treatment plans combine one or more of the options below — a decision best made with a cardiac electrophysiologist after a proper diagnosis.
Reducing caffeine and alcohol, treating sleep apnoea, managing stress, maintaining a healthy weight, and staying hydrated. These measures also promote well-being and health in many other ways.
Anti-arrhythmic drugs such as beta-blockers, calcium channel blockers, flecainide, propafenone, sotalol, or amiodarone are prescribed depending on the rhythm. These control symptoms and reduce episode frequency, and are often the initial treatment tried before considering a procedure.
A minimally invasive procedure that treats the abnormal electrical tissue directly. Curative for SVT, AVNRT, WPW, and atrial flutter (95–98%). Atrial fibrillation success rates range from 50–80% depending on AF type and number of procedures.
Learn about catheter ablation →A small device implanted under the skin that sends electrical signals to restore a normal heart rate. Used for bradycardia and heart block.
A device that continuously monitors the heart and delivers a shock if a dangerous ventricular arrhythmia occurs. Used in patients at high risk of sudden cardiac arrest.
A controlled electrical shock under sedation that resets the heart back to a normal rhythm. Typically used for persistent atrial fibrillation or atrial flutter.
For patients with atrial fibrillation, blood thinners such as apixaban, rivaroxaban, or dabigatran reduce the risk of stroke based on your individual CHA₂DS₂-VASc score.
Controlling blood pressure, thyroid disease, diabetes, sleep apnoea, and coronary artery disease is essential — often the arrhythmia resolves once the underlying cause is treated.
Ready to discuss your treatment options? Speak with Dr Paul Lim.
Many arrhythmias can be cured or very well controlled with modern treatment. Conditions related to short circuits in the heart such as SVT, AVNRT, AVRT, WPW syndrome, and typical atrial flutter have catheter ablation cure rates of 95–98%. Atrial fibrillation responds to ablation in 50–80% of patients, depending on the type of AF and the number of procedures. Benign extra beats usually need no treatment at all unless they are very frequent.
Some chronic arrhythmias such as long-standing atrial fibrillation are more often managed than cured — rate-controlled with medication, rhythm-controlled with ablation or cardioversion, paced with a pacemaker, and protected against stroke with anticoagulation. With appropriate management, most patients live a normal life expectancy and lead a full, active life.
Because treatment has advanced dramatically over the last two decades, a second opinion with a cardiac electrophysiologist is often worthwhile — particularly if your condition has been treated with medication alone for some time without success.
You cannot prevent every arrhythmia — some are genetic or structural — but you can substantially reduce your risk with the following steps.
Answers to the most common questions about irregular heartbeats, arrhythmia causes, symptoms, dangers, and treatment.
Medically called a cardiac arrhythmia, it is any disturbance in the normal rate or rhythm of your heartbeat. It can feel like skipping, fluttering, pounding, racing, or an unusually slow pulse. Episodes can be completely harmless or a sign of an underlying heart condition, which is why persistent or symptomatic irregularities should be evaluated by a cardiologist.
Seek urgent medical attention if it is accompanied by chest pain, severe shortness of breath, fainting, weakness down one side of the body, or a racing heart rate that does not settle. Book a specialist appointment promptly if episodes are frequent, last more than a few minutes, are triggered by exercise, occur with dizziness or fatigue, or if you have a family history of sudden cardiac death or inherited heart conditions.
Common causes include coronary artery disease, high blood pressure, thyroid disease, electrolyte imbalances (low potassium or magnesium), obstructive sleep apnoea, excessive alcohol or caffeine, emotional stress, certain medications, and age-related changes in the heart’s electrical system. In many younger patients no underlying cause is found and the irregularity is benign.
Many cases, including occasional extra beats (PACs or PVCs), are benign and not dangerous. However, sustained or complex arrhythmias such as atrial fibrillation and ventricular tachycardia can increase the risk of stroke, heart failure, or sudden cardiac arrest. A cardiologist evaluation with an ECG and, where needed, a Holter monitor will determine the severity and whether treatment is needed.
Yes. Emotional stress, anxiety, and panic can trigger temporary palpitations and extra beats by releasing adrenaline, which stimulates the heart. These episodes are usually harmless but can be distressing. If they are frequent or sustained, it is still sensible to have an ECG to rule out an underlying arrhythmia before attributing them to anxiety alone.
Yes — specifically atrial fibrillation (AFib), the most common sustained arrhythmia, increases stroke risk roughly 5-fold because blood can pool and form clots in the upper chambers of the heart. These clots can travel to the brain. This is why anticoagulation (blood thinners) is used to reduce stroke risk in AFib patients based on their individual CHA₂DS₂-VASc score.
Check your pulse at the wrist or neck while sitting quietly. A regular pulse taps steadily; an irregular one feels uneven, with missed or extra beats. Smartwatches (Apple Watch, Samsung Galaxy Watch, Fitbit, Garmin) and home blood pressure monitors can also detect irregular pulses (though not always entirely accurate). Any suspected abnormality should still be confirmed with a proper ECG recorded by a clinician.
Diagnosis begins with a clinical history and an electrocardiogram (ECG). Because arrhythmias often come and go, a 24-hour or longer prolonged ECG monitor called a Holter may be used to catch intermittent episodes. An echocardiogram checks the heart’s structure and function. In selected patients, an electrophysiology study (EPS) pinpoints the exact origin of the arrhythmia.
Treatment depends on the type of arrhythmia and its cause. Options include lifestyle changes, anti-arrhythmic medications, catheter ablation to treat the underlying electrical source, pacemaker implantation for slow heart rhythms, implantable defibrillators for high-risk ventricular arrhythmias, and cardioversion to restore normal rhythm. A cardiac electrophysiology consultation determines the right approach for you.
In many cases, yes. Supraventricular tachycardias, AVNRT, AVRT, WPW syndrome, and typical atrial flutter have catheter ablation cure rates of 95–98%. Paroxysmal atrial fibrillation can be well controlled in the majority of patients with ablation. Some arrhythmias are managed rather than cured — slow rhythms are treated with a pacemaker, and some chronic atrial fibrillation is rate-controlled with medication.
Most people with a well-managed arrhythmia live a normal life expectancy. Benign extra beats have no effect on lifespan. Atrial fibrillation, when properly treated with anticoagulation and rhythm or rate control, is compatible with a full lifespan. Life expectancy is more affected by the underlying heart condition and stroke risk than by the rhythm disturbance itself — which is why early specialist evaluation matters.
Common triggers include excess caffeine (strong coffee, energy drinks), alcohol especially binge drinking, very large meals, high-salt processed foods, and stimulant supplements. Dehydration and low potassium or magnesium can also trigger irregular beats. Avoiding personal triggers and maintaining good hydration, sleep, and a balanced diet reduces the frequency of many benign arrhythmias.
Yes — benign extra beats, stress-related palpitations, and short runs triggered by caffeine, alcohol, or poor sleep often resolve within minutes to hours once the trigger is removed. Paroxysmal atrial fibrillation by definition returns to normal rhythm spontaneously, usually within 24–48 hours. However, longer and increasingly frequent episodes lasting more than a day should warrant medical attention, as untreated arrhythmias like AFib can progress from paroxysmal to persistent over time.
The symbol on an Omron, Braun, or similar device means it detected an uneven time interval between heartbeats during your reading. It is a screening feature, not a diagnosis. It can reflect movement, talking, crossed legs, or a single extra beat. If the symbol appears once or twice, repeat the measurement after sitting still for five minutes. If it keeps appearing across several readings, book a cardiologist appointment for a proper 12-lead ECG to confirm whether you have a true arrhythmia.
It can point to anything from completely benign to serious. Common benign causes include harmless extra beats (PACs or PVCs), caffeine or alcohol excess, stress, dehydration, or poor sleep. More significant conditions include atrial fibrillation, supraventricular tachycardia, heart block, thyroid disease, electrolyte imbalance, coronary artery disease, heart failure, or sleep apnoea. Because the causes overlap, the only way to determine the underlying reason is a proper cardiac evaluation — an ECG is the definitive first test.
In most cases light to moderate exercise is safe and beneficial for people with irregular heartbeats. However, if you experience chest pain, severe breathlessness, dizziness, or fainting during exercise, stop immediately and seek medical review. If you have a diagnosed arrhythmia, your cardiologist can advise on a safe exercise plan, which may include a stress test or exercise ECG.
Most people with a stable, well-managed irregular heartbeat can fly safely. Long flights increase the risk of dehydration and deep vein thrombosis, so drink plenty of water, avoid alcohol, and move around the cabin regularly. If you are on anticoagulation for AF, ensure you have adequate medication supply and carry medical documentation. If your arrhythmia is new, unstable, or associated with fainting, chest pain, or heart failure symptoms, see a cardiologist before travel.
Yes. Atrial fibrillation alone affects roughly 10% of people over 80. Ageing causes gradual fibrosis of the heart’s electrical system, and older patients are more likely to have high blood pressure, valve disease, and other conditions that drive arrhythmias. The good news is that modern treatments work just as well in older patients when applied carefully.
Short, direct answers to the questions we are asked most often about irregular heartbeats.