ERA. 1  baseball, baseball game - a ball game played with a bat and ball between two teams of nine players; teams take turns at bat trying to score runs; he played baseball in high school; there was a baseball game on every empty lot; there was a desire for National League ball in the area; play ball!.
The contraction of the heart muscle starts in the two atria, which push the blood into the ventricles. Then the walls of the ventricles squeeze together and force the blood out into the arteries: the aorta to the body and the pulmonary artery to the lungs.
However, over time deposits of fatty substances, cholesterol, cellular waste products, calcium and other substances can build up in your arteries. These plaques can severely restrict blood flow and, even more seriously, they can cause your arteries to rupture, leading to blood clots. Blood clots can then block your blood flow entirely, leading to heart attack and stroke. In fact, a build-up of plaques in your arteries, known as atherosclerosis, is the main underlying cause of heart disease.