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.
Calcification of a valve may also result in stenosis. This causes the heart muscle to work harder to push blood through the narrowed opening. Like any muscle that has to work harder, heart muscle will hypertrophy and thicken. Heart failure, where fluid builds up in the lungs and extremeties, may be a complication.