1.29. Cardiovascular Diseases http://www.ck12.org
FIGURE 1.51
Atherosclerosis is sometimes referred to
as hardening of the arteries; plaque build-
up decreases the blood flow through the
artery.Coronary Heart Disease
Like any other muscle, your heart needs oxygen. Hearts have arteries that provide oxygen through the blood. They
are known ascoronary arteries.Coronary heart diseaseis the end result of the buildup of plaque within the walls
of the coronary arteries.
Coronary heart disease often does not have any symptoms. A symptom of coronary heart disease is chest pain.
Occasional chest pain can happen during times of stress or physical activity. The pain of angina means the heart
muscle fibers need more oxygen than they are getting. Most people with coronary heart disease often have no
symptoms for many years until they have a heart attack.
Aheart attackhappens when the blood cannot reach the heart because a blood vessel is blocked. If cardiac muscle
is starved of oxygen for more than roughly five minutes, it will die. Cardiac muscle cells cannot be replaced, so once
they die, they are dead forever. Coronary heart disease is the leading cause of death of adults in the United States.
The image below shows the way in which a blocked coronary artery can cause a heart attack and cause part of the
heart muscle to die (Figure1.52).
FIGURE 1.52
A blockage in a coronary artery stops
oxygen from getting to part of the heart
muscle, so areas of the heart that depend
on the blood flow from the blocked artery
are starved of oxygen.