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.
1 HBP adds to the workload of the heart. The narrowed arteries reduce the blood's ability to travel through the body smoothly. This adds to the workload on the heart, making it work harder than normal.  HBP can cause the heart to enlarge and fail to supply the needed blood to the body.