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.
Angina is usually due to heart disease. A fatty substance called plaque builds up in your arteries, blocking blood flow to the heart muscle. This forces your heart to work with less oxygen. That causes pain. You may also have blood clots in the arteries of your heart, which can cause heart attacks.