It depends on the setting. Outside a medical facility, or when medical personnel are absent from the scene, it is best to familiarize yourself with the symptoms, which are common to most heart attack sufferers: Numbness or pain the left arm, difficulty breathing or moving, and angina/chest pains. While these alone are not enough to diagnose, they are enough to cause a person to seek immediate medical attention.
Within a medical facility, a number of tests can be run to quickly determine whether a heart attack has taken place, its degree of severity and any damage it might have caused. An EKG, also known as an electrocardiogram, can monitor heart muscle activity to determine if there are abnormal heartbeats, while a sonogram of the heart can detect valve and tissue damage and monitor blood flow through the heart. Another test, though it takes longer, is a Myoglobin Test, which can be used to assess any damage that may have occurred in a patient with heart attack symptoms.
After you call 911 for a heart attack, paramedics will quickly assess your heart rate, blood pressure, and breathing rate. They also will place electrodes on your chest for an electrocardiogram (EKG, ECG)to check your heart's electrical activity.
When you arrive at the hospital, the emergency room doctor will take your history and do a physical exam, and a more complete ECG will be done. A technician will draw blood to test for cardiac enzymes, which are released into the bloodstream when heart cells die.
If your tests show that you are at risk of having or are having a heart attack, your doctor will probably recommend that you have cardiac catheterization. The doctor can then see whether your coronary arteries are blocked and how your heart functions.
If an artery appears blocked, angioplasty—a procedure to open up clogged arteries—may be done during the catheterization. Or you will be referred to a cardiovascular surgeon for coronary artery bypass graft surgery.
If your tests do not clearly show a heart attack or unstable angina and you do not have other risk factors (such as a previous heart attack), you will probably have other tests. These may include acardiac perfusion scan or SPECT imaging test.
If your tests do not show signs of a heart attack but your doctor thinks you have unstable angina and may be in danger of having a heart attack, you will be admitted to the hospital.