Common cardiac arrhythmia characterised by irregular pulse due to the loss of the regular atrial electrical activity.
Its onset can be acute or chronic, and it can be symptomatic or asymptomatic.

Risk factors

  • Heart disease (heart failure, valvular heart diseases, ischaemic heart disease)
  • Thyroid disease (hyperthyroidism)

Clinical features

  • Irregular pulse (frequency and volume), heart rate can be either normal or very high
  • Acute onset (often with high heart rate): palpitations, dizziness, fainting, chest pain, shortness of breath
  • Chronic (with normal or almost normal heart rate): often asymptomatic, discovered at routine checks
  • It can precipitate heart failure or pulmonary oedema
  • It can cause embolic stroke if clots form in the heart and are then dislodged to the brain circulation


  • ECG


  • Control heart rate
  • Restore normal rhythm if possible (specialist only)
  • Prevent or treat complications
  • Treat underlying conditions


If acute onset, high heart rate or patient in congestive heart failure and/or pulmonary oedema:

  • Treat heart failure, use digoxin and or carvedilol to reduce heart rate

If acute onset and high heart rate but no signs of heart failure:

  • Use atenolol 50 mg to control heart rate

If chronic but normal heart rate:

  • Only treat underlying conditions
  • Refer to assess indication for anticoagulation with aspirin or warfarin to
    prevent stroke