What is coronary artery disease?
Coronary artery disease is the narrowing or blockage of the coronary
arteries caused by atherosclerosis. Atherosclerosis (sometimes called
“hardening” or “clogging” of the arteries) is the buildup of cholesterol and
fatty deposits (called plaque) on the inner walls of the arteries that restricts
blood flow to the heart. Without adequate blood, the heart becomes starved of
oxygen and the vital nutrients it needs to work properly. This can cause chest
pain called angina. When one or more of the coronary arteries are completely
blocked, a heart attack (injury to the heart muscle) may occur.
The process of coronary artery disease
Your coronary arteries are shaped like hollow tubes through which blood can flow
freely. The walls of the coronary arteries are normally smooth and elastic.
Coronary artery disease starts when you are very young. Before your teen
years, the blood vessel walls begin to show streaks of fat.

With coronary artery disease, as you get older, the fat builds up, causing
slight injury to your blood vessel walls. In an attempt to heal the blood vessel
walls, the cells release chemicals that make the blood vessel walls stickier.
Other substances traveling through your blood stream, such as inflammatory
cells, cellular waste products, proteins and calcium, begin to stick to the
vessel walls. The fat and other substances combine to form a material called
plaque.

Over time, with coronary artery disease, the inside of the arteries
develop plaques of different sizes. Many of the plaque deposits are soft on the
inside with a hard fibrous “cap” covering the outside. If the hard surface
cracks or tears, the soft, fatty inside is exposed. Platelets (disc-shaped
particles in the blood that aid clotting) come to the area, and blood clots form
around the plaque.

This causes the artery to narrow even more. Sometimes, the blood clot breaks
apart, and blood supply is restored.

In other cases, the blood clot may totally block the blood supply to the heart
muscle, called a coronary thrombus or coronary occlusion - causing an acute
coronary syndrome.

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