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.
These changes make it hard for your heart to push blood through your pulmonary arteries and into your lungs. As a result, the pressure in your arteries rises. Also, because your heart is working harder than normal, your right ventricle becomes strained and weak. Your heart may become so weak that it can't pump enough blood to your lungs. This causes heart failure.