What should you know about an ECG electrocardiogram?

The tracing can help assess an irregular rhythm, changes linked with reduced blood flow to the heart, or electrical conduction problems. It may be part of an assessment for palpitations, chest discomfort, fainting, or breathlessness. A single ECG captures a limited period, so a normal result may not explain symptoms that come and go.

Wear clothing that allows access to the chest and limbs, and tell the clinician about medicines, implanted devices, and current symptoms. During the recording, lie still and breathe normally. The test itself does not send electricity into your body. Your clinician will explain whether the result is enough or whether monitoring or another test is needed.

Seek emergency help for severe or persistent chest pain, major difficulty breathing, fainting, collapse, or sudden weakness, confusion, or trouble speaking. An ECG appointment should not delay urgent assessment. Symptoms can require treatment even before the tracing is complete.

Ask what the tracing shows, whether it explains your symptoms, and whether you need repeat testing or longer rhythm monitoring. If a condition such as angina, atrial fibrillation, or heart failure is being considered, ask what findings support that possibility and what the next step will be.