Heart Attack: What Is It?

The Heart Needs Oxygen

The heart works by pumping blood to the rest of the body, day in and day out. Blood is filled with oxygen and nutrients that are needed to keep us alive. Blood travels through a network of tubes or vessels called arteries. The arteries that carry the blood with oxygen to the heart muscle are called coronary arteries. The heart muscle needs oxygen to live, just like other muscles in the body.

A heart attack occurs when the heart does not get enough oxygen

Heart attack is sometimes called myocardial infarction (my-oh-CARdee-ul- in-FARK-shun) or MI for short. This damages the heart and it stops working properly.

Blood flow slows with CAD

Heart attacks are often caused by coronary artery disease (CAD). In CAD, the coronary arteries become narrow. Fatty substances called plaques attach to the inside of the coronary arteries and cause the narrowing. This process is called atherosclerosis (ATH-er-oh-skler-OH-sis). As a result of the narrowing, blood cannot flow properly through the arteries and take oxygen to the heart muscle.

Atherosclerosis occurs over many years. At first, the person may feel fine. This is because blood and oxygen can still reach the heart muscle, even though the coronary arteries are narrowed. But as time goes by, the arteries become so narrow that blood and oxygen have trouble getting to the heart muscle. This condition is called ischemia (iss-KEE-me-uh). When ischemia occurs, the body shows signs that something is wrong.

Warning Signs

With ischemia, the patient may notice chest pain, or angina (AN-ji-nuh). This pain is different in every patient. Common complaints of angina are:

  • Pain in the left side or center of the chest
  • Pain that travels down the arm or into the jaw area
  • Pain between the shoulder blades
  • A feeling of “indigestion”

The pain of angina can be mild or severe. It can come and go, or it may be constant. Angina can be a warning sign for a heart attack.

A heart attack occurs when the blood supply to part of the heart muscle is completely cut off.

This can happen when CAD has narrowed the coronary arteries so much that blood cannot flow through. Or it can happen if a blood clot forms and blocks the blood supply to the heart muscle. Either way, oxygen is unable to reach the heart muscle. As a result, heart cells become damaged and begin to die.

Heart Attack Signs

Chest pain is the main sign of a heart attack, though this sign is more common in men than in women. Some other signs are:

  • Shortness of breath
  • Nausea
  • Vomiting
  • Sweating
  • Dizziness
  • A fast heartbeat
  • Extreme weakness

Call for Help

If you think you are having a heart attack, seek medical treatment immediately.

Early treatment within the first few hours of a heart attack can save your life. And it can reduce the damage caused by a heart attack. If you have any signs of a heart attack:  

  • Call 911 immediately for the safest and quickest transportation to the hospital.
  • Do not drive yourself to the emergency department.
  • Do not have a family member drive you to the emergency department.

The quicker you get to the hospital, the less damage will occur to your heart.

UPMC | Affiliated with the University of Pittsburgh Schools of the Health Sciences | Supplemental content provided by Healthwise, Incorporated. To learn more, visit www.healthwise.org

For help in finding a doctor or health service that suits your needs, call the UPMC Referral Service at 412-647-UPMC (8762) or 1-800-533-UPMC (8762). Select option 1.

UPMC is an equal opportunity employer. UPMC policy prohibits discrimination or harassment on the basis of race, color, religion, ancestry, national origin, age, sex, genetics, sexual orientation, gender identity, marital status, familial status, disability, veteran status, or any other legally protected group status. Further, UPMC will continue to support and promote equal employment opportunity, human dignity, and racial, ethnic, and cultural diversity. This policy applies to admissions, employment, and access to and treatment in UPMC programs and activities. This commitment is made by UPMC in accordance with federal, state, and/or local laws and regulations.

Medical information made available on UPMC.com is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. Further, UPMC.com is not a tool to be used in the case of an emergency. If an emergency arises, you should seek appropriate emergency medical services.

Pittsburgh, PA, USA | UPMC.com