Overview
Heart arrhythmias are abnormal heart rhythms where the heart beats too fast (tachycardia), too slow (bradycardia), or in an irregular pattern. Atrial fibrillation (AF) is the most common significant arrhythmia. Some arrhythmias are harmless; others can cause stroke, heart failure, or cardiac arrest.
How common is it?
Atrial fibrillation affects about 1.5 million people in the UK. It becomes increasingly common with age, affecting about 10% of people over 80.
Causes and risk factors
Arrhythmias arise from abnormalities in the heart's electrical conduction system. Many result from underlying heart disease but some occur in otherwise healthy hearts.
Common risk factors
- High blood pressure (the most important modifiable risk factor for AF)
- Coronary artery disease
- Heart valve disease
- Thyroid overactivity
- Alcohol excess ('holiday heart syndrome')
- Sleep apnoea
- Age
- Obesity
Symptoms
- Palpitations: racing, fluttering, or irregular heartbeat sensation
- Breathlessness
- Dizziness or light-headedness
- Chest discomfort
- Fatigue
- Fainting (more serious arrhythmias)
- Some people with AF have no symptoms
When to see a doctor
Go to A&E for palpitations with chest pain, breathlessness, fainting, or collapse. See your doctor urgently for new rapid irregular heartbeat. Persistent palpitations require investigation.
Diagnosis
ECG during symptoms is diagnostic. 24 to 72-hour Holter monitor or 2-week event recorder captures intermittent arrhythmias. Echocardiogram assesses cardiac structure. Thyroid function blood test excludes thyroid cause.
Treatments
Rate or rhythm control medication
Beta-blockers, digoxin, and calcium channel blockers control the rate in AF. Antiarrhythmic drugs (flecainide, amiodarone) restore and maintain normal rhythm.
Anticoagulation
Direct oral anticoagulants (apixaban, rivaroxaban) or warfarin dramatically reduce stroke risk in AF by preventing clot formation in the heart. Risk is assessed using the CHA2DS2-VASc score.
Catheter ablation
A procedure using radiofrequency or cryotherapy energy delivered through catheters to destroy the abnormal electrical pathways or triggers causing the arrhythmia. Increasingly effective for paroxysmal AF.
Self-care and lifestyle
- Control blood pressure as it is the most important modifiable risk factor for AF
- Reduce or eliminate alcohol as even moderate intake increases AF risk
- Treat sleep apnoea which is a strong driver of AF recurrence
- Take anticoagulation medication consistently and have INR monitoring if on warfarin
Prevention
Treating high blood pressure, limiting alcohol, maintaining healthy weight, treating sleep apnoea, and staying active reduce the risk of developing AF and other arrhythmias.