Premature Atrial Contractions

Premature atrial contractions (atrial ectopic beats) are early beats arising from an ectopic focus in the atria, which interrupt the regular rhythm. They are extremely common, occur in healthy people of all ages, and are usually benign.

• Triggers: caffeine, alcohol, nicotine, stimulants, stress, sleep deprivation, electrolyte disturbance, thyrotoxicosis, anaemia, febrile illness, sympathomimetic drugs and decongestants.
• Associated with structural disease: valvular heart disease, atrial enlargement, hypertension, heart failure, chronic lung disease, ischaemia.
• Frequent premature atrial contractions can be a marker for future atrial fibrillation, particularly in older adults.
• Prognosis is excellent in structurally normal hearts.

• Palpitations described as skipped beats, flutters, thumps, or a pause followed by a forceful beat.
• Often noticed at rest, in the evening or lying down; may be asymptomatic.
• Occasionally light headedness or anxiety.
• Examination: irregularly irregular or regularly irregular pulse that disappears with exercise; normal heart sounds.
• Red flags: syncope, chest pain, dyspnoea, family history of sudden death, structural heart disease, sustained palpitations.

• 12-lead ECG: early P wave of different morphology followed by a normal narrow QRS; the P wave may be hidden in the preceding T wave; a non-compensatory pause usually follows. Blocked atrial ectopics produce a pause without QRS.
• Bloods: thyroid function, full blood count, urea and electrolytes, magnesium.
• 24 to 48 hour ambulatory ECG (or 7-day patch) to quantify burden and exclude atrial fibrillation or sustained tachycardia.
• Echocardiography if frequent ectopics, symptoms, murmur or abnormal ECG.
• Differentials: premature ventricular contractions, atrial fibrillation, atrial flutter, sinus arrhythmia.

Reassurance and lifestyle (mainstay)

• Explain benign nature. Reduce caffeine, alcohol, nicotine, energy drinks, recreational stimulants; treat anxiety and sleep problems; stop or change sympathomimetic medicines.
• Correct electrolyte and thyroid disorders.

Pharmacological (only if bothersome symptoms)

• Bisoprolol 1.25 to 5 mg orally once daily, or propranolol 10 to 40 mg orally two or three times daily, or metoprolol 25 to 50 mg orally twice daily. Contraindicated in asthma, severe bradycardia and heart block.
• Verapamil modified release 120 to 240 mg orally once daily is an alternative if beta blockers are not tolerated (avoid in heart failure with reduced ejection fraction, heart block and with beta blockers).
• Review after 4 to 6 weeks and withdraw gradually if symptoms resolve.

Special groups

• Pregnancy: ectopy is common and benign; avoid medication unless severe, and use beta blockers only with specialist advice.
• Athletes: benign if no symptoms or structural disease.
• Older adults: check for atrial fibrillation with prolonged monitoring; assess stroke risk if atrial fibrillation is documented.

Follow up and referral

• Refer if ectopic burden is high, structural heart disease is suspected, symptoms persist despite treatment or runs of tachycardia are seen.