The efficiency of the human heart is a beautiful thing. All four chambers work in a beautiful, synchronized effort to do one thing well: push blood. When disease compromises the heart's ability to function, the result is often a reduction in "ejection fraction" (EF) or the percentage of the end diastolic volume ejected with each contraction. What is a normal value for EF at rest?
A)50-60%
B)60-70%
C)60-80%
D)70-80%

Question

Quizplus · Accepted Answer

Ejection fraction is basically a measure of efficiency: how much blood is pushed and how much is left lingering in the heart? At rest, the normal human heart is not nearly as efficient as during exercise; only 50-60% of the end diastolic volume is pushed out of the heart with each contraction.

The Efficiency of the Human Heart Is a Beautiful Thing