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.
If a clot blocks blood flow to the heart, it can cause a heart attack. This picture shows how CAD causes a heart attack. Plaque builds up in an artery of the heart, and a blood clot forms. The clot blocks blood flow to part of the heart, and the heart muscle begins to die.