What to expect from an ECG for a heart attack

The tracing shows how electrical activity travels through the heart. Certain patterns can support a heart attack diagnosis, suggest which area may be affected, or reveal another cause of chest symptoms. An ECG is interpreted alongside your symptoms, examination, blood tests, and sometimes imaging.

The test involves lying still while adhesive sensors are placed on your chest and limbs. It takes only a short time and does not deliver an electrical shock. Staff may repeat it because electrical changes can evolve, or if symptoms continue.

Tell the team when your symptoms began, where discomfort is located, and whether you have breathlessness, sweating, nausea, or faintness. Share your medicines, allergies, and relevant heart history if you can do so safely.

Remain available for further tests and treatment while the team reviews the results. Do not drive yourself if you have concerning chest symptoms. Follow the emergency team’s instructions even if the first tracing is not clearly abnormal.

Call emergency services immediately for chest pressure, squeezing, or pain that lasts or returns, especially with breathlessness, sweating, nausea, fainting, or pain spreading to the arm, back, neck, or jaw. Do not wait for an ECG appointment.

Ask what your ECG showed, whether blood tests or repeat recordings are needed, what treatment is being considered, and which symptoms should trigger emergency help after you leave.