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.
More commonly, we just call this a heart attack. When the blood supply is cut off to the heart, the heart muscle doesn't receive oxygen, resulting in injury. So, just like an injured athlete slows down, so too does an injured heart. Another cause of bradycardia is hypertension, or high blood pressure. High blood pressure makes it very difficult for your heart to push blood out into circulation and causes a reflex in your body (called reflex bradycardia) that slows down the heart in order to try and lower the blood pressure.