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 reason PACs or PVCs can sometimes be felt as a skipped beat, is that the heart gets a premature signal to squeeze before it has had time to fill with blood. The resulting heart contraction does not produce blood flow to the body. A pause is felt, and the following heart beat is more forceful than usual. If the PAC or PVC is less premature, and the heart has had time to fill with blood before receiving the early signal to squeeze, an extra beat will be felt rather than a skipped beat. Premature beats are common in healthy people of all ages.