What is a Heart Attack?

Heart attacks are often thought of as a sudden, pressure-like chest pain that takes a person by complete surprise. But heart attacks can have early warning signs, and often result from heart disease that builds up over time. A key to preventing a heart attack is knowing the risk factors that can lead to heart disease and knowing the early warning signs.

What Causes Heart Attacks?

The two main causes of heart attacks are:

• Coronary artery blockage
• Coronary artery disease

What Happens During a Heart Attack?

A network of blood vessels, known as coronary arteries, surrounds the heart muscle and supplies it with blood that is rich in oxygen. The heart muscle needs this oxygen to function.

A heart attack occurs when a coronary artery becomes suddenly blocked, stopping the flow of blood to the heart muscle and damaging it. All or part of the heart muscle becomes cut off from its oxygen supply. Left without oxygen, the heart muscle is injured.

What Is Coronary Artery Disease?

Coronary artery disease (also known as atherosclerosis or hardening of the arteries) occurs when fatty deposits build up within the artery walls. Over time, the fatty deposits harden, narrowing the passageway inside the blood vessel. The narrowed artery limits or pinches off the flow of blood to the heart muscle.

The rough, hardened surface of the artery also encourages small blood clots to form. Most heart attacks result when a blood clot forms in a narrowed artery. The blood clot blocks the artery and prevents blood from reaching part of the heart muscle.