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.
The most common form, dilated cardiomyopathy (DCM), occurs when your heart muscle is too weak to pump blood efficiently. The muscles stretch and become thinner. This allows the chambers of your heart to expand. This is also known as enlarged heart. You can inherit it, or it can be due to coronary artery disease.