Angina and myocardial infarction: what you should know

Angina describes symptoms rather than permanent heart muscle damage. Stable angina often follows a predictable trigger, such as physical effort, and improves with rest or prescribed medicine. New chest discomfort, symptoms occurring at rest, or a change in a familiar angina pattern may represent unstable angina and needs urgent assessment.

A myocardial infarction, commonly called a heart attack, occurs when restricted blood flow lasts long enough to injure heart muscle. Possible features include pressure, heaviness, squeezing or burning in the chest; discomfort spreading to an arm, shoulder, back, neck or jaw; breathlessness; sweating; nausea; or sudden weakness. Some people have less typical symptoms, so the absence of severe pain does not rule it out.

Stop activity and sit in a safe place. If you have an angina action plan, follow it and use prescribed medication exactly as directed. Do not drive yourself if symptoms are new, severe, persistent, occur at rest or differ from your usual angina; call emergency services instead.

Assessment may include a clinical examination, an electrocardiogram and blood tests that look for heart muscle injury. Treatment depends on whether blood flow is temporarily reduced or an artery is blocked, as well as the person's symptoms, test results and other health conditions.

Call emergency services immediately for chest pressure or pain that is severe, does not settle promptly with rest and prescribed medicine, or is accompanied by breathlessness, faintness, cold sweating, nausea or discomfort spreading beyond the chest. Treat new symptoms at rest and a sudden change in established angina as emergencies. While waiting, remain at rest and follow the emergency operator's instructions.

Ask what triggers should prompt emergency help, how to use each prescribed medicine, and whether your current symptoms fit a stable pattern. Discuss blood pressure, blood glucose, cholesterol, smoking, activity and family history so your clinician can explain which heart risks are most relevant to you.