Investigating Palpitations

Key points

• Possible causes: arrhythmias · stress · increased awareness of normal heart beat / extrasystoles
• First-line investigations: 12-lead ECG · thyroid function tests (thyrotoxicosis may precipitate atrial fibrillation) · urea and electrolytes (low potassium) · full blood count
• A 12-lead ECG captures only a few seconds of rhythm, so it is likely to miss episodic arrhythmias; it may still show a prolonged QT or PR interval or changes suggesting recent myocardial ischaemia
• Holter monitor: portable battery-operated device recording continuous ECG from 2-3 leads, usually for 24 hours (longer if symptoms are less than daily); patient keeps a symptom diary to compare with the rhythm strip
• If the Holter is normal and symptoms continue → external loop recorder, then implantable loop recorder

Decision points in this pathway

• First-line investigations normal but an episodic arrhythmia is suspected?
• Holter monitor normal and symptoms continue?

The full step-by-step algorithm, including what to do at each branch, opens in the app for approved members.