Learning About Different Types of Heart Attacks

A heart attack is an event that occurs when part of the heart muscle does not get enough blood and oxygen. This part of the heart starts to die.

A heart attack doesn't have to be deadly. Quick treatment can restore blood flow to the heart and save your life.

Your doctor might call a heart attack a myocardial infarction, or MI. Your doctor might also use the term acute coronary syndrome for a heart attack.

The two main types of heart attacks are:

• STEMI. This is a complete blockage of blood and oxygen to a heart artery. STEMI stands for "ST-elevation myocardial infarction."
• NSTEMI. This is a partial blockage or reduction of blood and oxygen to a heart artery. NSTEMI stands for "non-ST-elevation myocardial infarction."

Both types of heart attacks, STEMI and NSTEMI, are caused when not enough blood and oxygen reach part of the heart muscle.

This most often happens because blood flow through one or more coronary arteries is blocked or reduced. In most cases of STEMI and NSTEMI, this blockage or reduction is caused by a blood clot that forms when plaque (fatty deposits) in the artery breaks open.

STEMI and NSTEMI can have the same main symptoms. But symptoms can be different for each person. And people may have more than one symptom.

Symptoms of STEMI and NSTEMI may include:

• Chest pain or pressure or a strange feeling in the chest. This is the most common symptom.
• Shortness of breath.
• Sweating.
• Nausea or vomiting.
• Pain, pressure, or a strange feeling in the back, neck, jaw, or upper belly or in one or both shoulders or arms.
• Lightheadedness, sudden weakness, or passing out.
• Tiredness.
• A fast or irregular heartbeat.

People also describe the symptoms as discomfort, pressure, squeezing, or heaviness in the chest. The pain may spread down the left shoulder and arm and to other areas.

The doctor will take your health history, do a physical exam, and check your heart rate, blood pressure, and breathing rate. You will have tests that can help diagnose a heart attack. The tests include:

• Electrocardiogram (EKG, ECG). This test measures the electrical signals of the heart. It helps show whether you are having a heart attack.
• Troponin test. This is a blood test that looks for a rise in cardiac proteins. The heart muscle releases these proteins when it is damaged.
• Imaging tests. These tests provide images that show how well the heart is working and how well blood is flowing to the heart muscle. Examples include a CT angiogram, an echocardiogram, and an MRI.
• Coronary angiogram. This test can check blood flow in the coronary arteries.

An EKG helps find out which type of heart attack a person has had. An EKG takes several measurements, including one called an ST segment. If a person had a STEMI, the ST segment is raised. This is called ST-segment elevation.

If a person had an NSTEMI, the EKG doesn’t show the changes that are usually seen with a STEMI. With an NSTEMI, the ST segment in the EKG is not raised.

A STEMI can often be diagnosed with an EKG. An NSTEMI is most often diagnosed with a troponin test.

If you call 911, treatment will start in the ambulance. You may be given aspirin, oxygen, and pain medicine.

In the hospital, the doctor will work right away to return blood flow to your heart. You may be given:

• Medicine to prevent blood clots.
• Nitroglycerin. It opens up the arteries of the heart to help blood flow back to the heart.
• Other medicines, such as a beta-blocker.

Your test results will help your doctor decide about more treatment, such as:

• Angioplasty. This is a procedure to open a blocked artery so that blood can flow through it more easily. A STEMI is most often treated with angioplasty right away. An NSTEMI may be treated with angioplasty, but it may not be right away.
• Medicine to break up blood clots. It may be used with a STEMI but not with an NSTEMI.
• Bypass surgery. This surgery helps blood flow around, or bypass, one or more narrowed or blocked coronary arteries. Depending on the type of heart attack and how severe it is, some people have this surgery.

Before you leave the hospital, your doctor will start you on medicines to lower your risk of another heart attack and to treat other problems. You may get medicine to lower blood pressure, lower cholesterol, lower the heart’s workload, and prevent blood clots.

Cardiac rehabilitation (rehab) might be started in the hospital or soon after you go home. Cardiac rehab can help you feel better and reduce your risk for future heart problems.

Treatment at home focuses on a heart-healthy lifestyle. This lifestyle includes eating healthy, being active, staying at a weight that's healthy for you, and not smoking. It also includes taking medicines as directed, managing other health conditions, and trying to get a healthy amount of sleep.