How effective is an ECG for atrial fibrillation?

An ECG records the heart's electrical signals through sensors placed on the skin. During atrial fibrillation, the tracing may show an irregular rhythm and the absence of the usual organised atrial pattern. This helps a clinician distinguish atrial fibrillation from some other causes of a racing or uneven pulse.

A standard ECG captures only a brief window. If palpitations are occasional, the rhythm may settle before the test, leaving a normal result despite previous episodes. A clinician may then suggest a portable monitor worn for longer, depending on your symptoms and examination.

Tell the clinician when symptoms began, how long they last, and whether you notice breathlessness, chest discomfort, faintness or reduced exercise tolerance. Bring a list of medicines and mention thyroid problems, high blood pressure, sleep-related breathing problems or previous heart conditions.

Do not start, stop or change a medicine based on the tracing alone. The result is considered alongside your pulse, medical history and sometimes blood tests or heart imaging. Treatment decisions may include controlling the rhythm or rate and assessing ways to reduce clot-related risk.

Seek emergency help for chest pressure, severe breathlessness, collapse, new weakness on one side, trouble speaking, or sudden confusion. These symptoms can signal a serious heart or circulation problem and should not wait for a routine ECG appointment.

Arrange prompt medical review for a sustained fast or irregular heartbeat, repeated faintness, or new swelling and breathlessness. A normal reading between episodes does not explain away symptoms that continue.

Was atrial fibrillation captured on my ECG, or was the recording normal? Would longer rhythm monitoring help? What symptoms should prompt urgent assessment, and do I need tests to look for a cause or decide on treatment?