Try to remain calm and avoid emotional stress, as emotional excitement can increase the burden on the heart.
Immediately stop any physical activity, sit or lie down to rest, and reduce the burden on the heart.
If a heart attack is suspected and there is no history of aspirin allergy or bleeding disorders, chew one aspirin tablet (usually 300 mg) immediately. Aspirin can help reduce blood clot formation, but it should be taken under the guidance of a doctor.
If prescribed by a doctor and there are no contraindications, place one nitroglycerin tablet under the tongue. Nitroglycerin can help dilate the coronary arteries and increase blood supply to the myocardium.
If the patient loses consciousness or stops breathing, immediately perform cardiopulmonary resuscitation (CPR) and continue until emergency personnel arrive.
While waiting for emergency personnel to arrive, avoid giving the patient food or drink, as this may cause vomiting or choking during CPR.