Quick answer. An arrhythmia is an abnormal heart rhythm – the heart beating too fast, too slow or irregularly. Beyond atrial fibrillation (covered separately), common types include harmless extra beats (ectopics), supraventricular tachycardia or SVT (sudden fast bursts), bradycardia (a slow heart rate), and heart block (delayed electrical signals). Many palpitations are benign, but warning signs that need urgent attention include fainting, chest pain, severe breathlessness or a racing rhythm that does not settle. In Singapore, arrhythmias are diagnosed with an ECG and Holter (24-48 hour) monitoring. Treatment may involve medications, catheter ablation, or a pacemaker for slow rhythms. Collapse, chest pain or fainting with palpitations – call 995.
Your heart normally beats in a steady, coordinated rhythm driven by its own electrical system. An arrhythmia is any disturbance of that rhythm – the heart beating too fast, too slow, or irregularly. Many people feel this as palpitations: a pounding, fluttering or skipping sensation in the chest.
This guide covers heart rhythm disorders broadly, beyond atrial fibrillation, which is dealt with in our dedicated atrial fibrillation guide. We explain the main types – ectopic beats, SVT, bradycardia and heart block – how doctors in Singapore diagnose them with ECG and Holter monitoring, and the treatments available, from medications to catheter ablation and pacemakers. Crucially, it covers when palpitations are harmless and when they signal something serious.
At a glance
| Type | What it is | Usual significance |
|---|---|---|
| Ectopic / premature beats | Occasional extra beats felt as a skip or thud | Very common and usually harmless |
| Supraventricular tachycardia (SVT) | Sudden bursts of a fast, regular heartbeat from the upper chambers | Usually not life-threatening but can be very symptomatic; often curable with ablation |
| Bradycardia | A slow heart rate (under 60 beats per minute) | Can be normal in fit people, but causes tiredness, dizziness or fainting if too slow |
| Heart block | Delayed or blocked electrical signals between the chambers | Mild forms may be harmless; more severe forms may need a pacemaker |
| Ventricular arrhythmias | Fast rhythms from the lower chambers (VT/VF) | Can be life-threatening – a medical emergency |
How the heart's rhythm works
Each heartbeat starts with an electrical impulse in the heart’s natural pacemaker (the sinus node), which spreads through the chambers in an orderly way. A normal resting heart rate is roughly 60-100 beats per minute. An arrhythmia happens when this electrical signalling goes wrong – producing a rhythm that is too fast (tachycardia), too slow (bradycardia), or irregular. Some arrhythmias are completely harmless, while others need treatment, so identifying the specific type matters.
Common types of arrhythmia
- Ectopic (premature) beats – extra beats that feel like a skip, thud or flutter. They are extremely common, usually harmless, and most people have them at some point.
- Supraventricular tachycardia (SVT) – sudden episodes of a fast, regular heartbeat starting above the ventricles, often in younger adults. It is usually not life-threatening but can cause marked palpitations, breathlessness or dizziness, and is frequently curable with ablation.
- Bradycardia – a slow heart rate. This can be normal in athletes, but if too slow it causes fatigue, light-headedness or fainting.
- Heart block – the electrical signal between the upper and lower chambers is delayed or interrupted; severe forms can cause a dangerously slow pulse.
- Ventricular tachycardia and fibrillation – fast rhythms from the lower chambers that can be life-threatening and are emergencies.
Atrial fibrillation, the most common irregular rhythm, is covered in our separate atrial fibrillation guide.
Symptoms and how they feel
Arrhythmias can feel very different depending on the type:
- Fast rhythms – palpitations, a racing or pounding heartbeat, chest tightness, breathlessness or dizziness.
- Slow rhythms – fatigue, reduced exercise tolerance, light-headedness or fainting spells.
- Ectopic beats – a sensation of skipped or extra beats; many people have no symptoms at all.
Some people feel dramatic symptoms from a harmless rhythm, while others have a serious arrhythmia with few symptoms – which is why proper testing is important.
When palpitations are benign vs serious
Most palpitations are harmless, especially brief skips or flutters at rest, after caffeine, stress, or lack of sleep. Seek urgent help – call 995 if palpitations come with:
- Fainting or near-fainting (collapse)
- Chest pain or pressure
- Severe breathlessness
- A fast heartbeat that does not settle
Also see a doctor (non-emergency) if palpitations are frequent, prolonged, getting worse, or if you have known heart disease or a family history of sudden cardiac death. When in doubt, get it checked – a simple ECG often provides the answer.
Diagnosis – ECG and Holter monitoring
Because arrhythmias can come and go, the aim is to capture the rhythm while symptoms are happening:
- ECG (electrocardiogram) – a quick recording of the heart’s electrical activity; ideal if you happen to be having symptoms at the time.
- Holter monitor – a portable recorder worn for 24 to 48 hours (or longer) to catch intermittent rhythms.
- Event or loop recorders – worn over weeks for infrequent episodes.
- Exercise stress test, echocardiogram and blood tests – to look for triggers and underlying heart disease.
- Electrophysiology (EP) study – a specialised catheter test that maps the heart’s electrical circuits when ablation is being considered.
Treatment options
Treatment depends on the type, symptoms and any underlying cause:
- Reassurance and lifestyle measures – for harmless ectopics, cutting back on caffeine, alcohol and stimulants and improving sleep is often all that is needed.
- Medications – anti-arrhythmic and rate-controlling drugs to slow or steady the rhythm.
- Catheter ablation – a minimally invasive procedure that uses heat or freezing energy to destroy the small area of tissue causing the abnormal rhythm; it can cure many SVTs and is offered at centres such as NHCS.
- Pacemaker – a small implanted device for slow rhythms (bradycardia) or significant heart block, ensuring the heart does not beat too slowly.
- Implantable defibrillator (ICD) – for people at risk of dangerous fast ventricular rhythms.
Related guides
- Best Cardiology Clinics in Singapore — our editorial shortlist
- cardiology clinics directory
- Heart failure
- Coronary artery disease & angina
- Heart valve disease
Sources
- SingHealth – Abnormal Heart Rhythm (Arrhythmia)
- NHCS Murmurs – Arrhythmia: Is My Heart Pounding Normal?
- NHCS – Electrophysiology & Pacing
- HealthHub – Heart Arrhythmia
Related conditions & guides
Related conditions and guides you may find useful:
- Diabetes Complications in Singapore
- Heart Attack Warning Signs in Singapore
- Heart Screening in Singapore
- High Blood Pressure (Hypertension) in Singapore
- High Cholesterol in Singapore
- Heart Palpitations & Atrial Fibrillation (AFib) in Singapore
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