An arrhythmia is any deviation from the normal, regular heart rhythm — encompassing slow rhythms (bradycardia), fast rhythms (tachycardia), and irregular rhythms (such as atrial fibrillation).
The heart's normal rhythm originates from the sinoatrial (SA) node — the heart's natural pacemaker — generating 60–100 electrical impulses per minute at rest. An arrhythmia occurs when this system is disrupted: from problems with impulse generation, conduction, or re-entry circuits. Arrhythmias range enormously in clinical significance — from benign ectopic beats (felt as palpitations) to life-threatening ventricular fibrillation (VF) requiring immediate defibrillation.
Common arrhythmias include: atrial fibrillation (AF — the most prevalent sustained arrhythmia in adults, causing irregular, often rapid rhythm and stroke risk), supraventricular tachycardia (SVT — paroxysmal rapid regular heart rate), ventricular tachycardia (VT — originating in the ventricles, potentially life-threatening), and heart block (delayed or blocked conduction through the AV node, causing bradycardia). Diagnosis requires an ECG — a 12-lead ECG for symptomatic arrhythmias, Holter monitor for intermittent events.
Treatment depends on the type and haemodynamic impact: AF is managed with rate control, rhythm control, and anticoagulation (to prevent stroke). SVT is treated with vagal manoeuvres, adenosine, or ablation. Life-threatening ventricular arrhythmias may require an implantable cardioverter-defibrillator (ICD). Korea's major cardiac centres — including Samsung Medical Center, Asan Medical Center, and Severance Hospital — manage the full spectrum of arrhythmias with dedicated electrophysiology services.
Key Points
- AF is most common sustained arrhythmia — increases stroke risk
- ECG is the first-line diagnostic test
- VF requires immediate defibrillation — call 119
- Anticoagulation for AF reduces stroke risk by 60–70%
- Ablation cures many SVTs and some AF
Causes & Risk Factors
- Hypertension
- Coronary artery disease
- Cardiomyopathy
- Electrolyte abnormalities (low potassium, magnesium)
- Thyroid disease
- Stimulants (caffeine, drugs)
When to See a Doctor
- Palpitations with dizziness, fainting, or chest pain
- Irregular heartbeat on self-monitoring
- New palpitations in patients with heart disease
For emergencies in Korea, call 119
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This content is published for educational purposes only. For accurate diagnosis and personalised treatment, consult a licensed KMA physician in Korea.
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Medical Disclaimer
This article is published by DoctorsInKorea.com for educational and informational purposes only. It does not replace a professional clinical evaluation by a licensed healthcare provider. For accurate medical diagnosis and personalised treatment paths, please book an appointment with a licensed KMA physician. For immediate life-threatening medical emergencies in Korea, please call 119.
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Last reviewed: March 1, 2025