Cardiac Subspecialty Certification Practice Test

Ejection fraction specifically measures the amount of blood that is pumped out of the heart with each heartbeat, expressed as a percentage of the total volume of blood in the heart's chambers at the end of filling. It provides critical information about the heart's pumping efficiency and is often used to assess heart function, particularly in conditions such as heart failure.

A normal ejection fraction indicates that the heart is pumping well, whereas a reduced ejection fraction may signal heart dysfunction, which can lead to various cardiovascular diseases. Consequently, ejection fraction is a key metric in understanding the heart's performance during systole (the phase of the heartbeat when the heart muscle contracts).

Other choices, such as the volume of blood in the heart chambers, the electrical activity of the heart, or the size of the heart chambers, do not accurately reflect what ejection fraction quantifies. These aspects are related to heart function but are distinct measurements that serve different diagnostic purposes.