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.
This often preventable disease causes the dangerous thickening and narrowing of the coronary arteriesâthe vessels that bring blood to the heartâwhich disrupts the flow of oxygen and nutrients to the heart, causing serious problems. Without enough blood, coronary artery disease can lead to angina (chest pain). Over time, the heart has to work harder, possibly causing heart failure (when the heart cannot pump efficiently) or arrhythmia (when the heart beats irregularly or too quickly).