Can the heart ever pump at 100%?

Can the heart ever pump at 100%?

Heart can never pump at 100%. It can at the most pump at 80 – 90%. The pumping fraction (ejection fraction) is the fraction of blood which it pumps out when it contracts. For example, if it receives 100 ml when it relaxes and pumps out 70 ml on contraction, the ejection fraction is 70%. It is almost physically impossible for the heart to pump out the whole amount blood by squeezing itself. Some part of the blood which it receives when it relaxes always remains back at the fully contracted state of the heart.