In angiography, the term "ejection fraction" refers to:

• A. The volume of blood pumped per heartbeat
• B. The percentage of blood ejected from the ventricle
• C. The total blood volume in circulation
• D. The heart rate during physical exertion

Answer: (B)

Ejection fraction is a key measurement used in cardiology and angiography to assess the efficiency of the heart's pumping ability. It specifically refers to the percentage of blood that is ejected from the ventricles with each heartbeat. This measurement is crucial in evaluating cardiac function, particularly in patients with conditions such as heart failure, where the heart's ability to pump blood is compromised.

When discussing ejection fraction, it is calculated by taking the stroke volume (the amount of blood pumped out of the ventricle) and dividing it by the total volume of blood in the ventricle before contraction (end-diastolic volume). The result shows how well the heart is performing, with normal values typically ranging from 55% to 70%. This percentage helps clinicians determine the severity of heart disease and guide treatment decisions.

In contrast, the volume of blood pumped per heartbeat refers to stroke volume itself, which is a different measurement; total blood volume in circulation does not factor into the ejection fraction; and heart rate during physical exertion concerns the frequency of heartbeats but does not directly relate to the efficiency of blood ejection from the heart.