What does end-diastolic volume (EDV) represent?

End-diastolic volume (EDV) represents the volume of blood in each ventricle at the end of the filling phase, just before the heart contracts. This measurement is critical for evaluating cardiac function because it indicates how much blood is available in the ventricles to be propelled into the circulation during systole (the contraction phase).

Understanding EDV is essential for grasping concepts related to stroke volume, which is the amount of blood ejected by the heart with each contraction. A higher EDV typically allows for a greater stroke volume under normal physiological conditions, which is a reflection of how well the heart is functioning in terms of volume capacity. The relationship between EDV and cardiac output highlights the importance of filling pressure and ventricular compliance.

In distinguishing this from the other options, the volume of blood in the arteries describes a different aspect of hemodynamics, while the volume of blood ejected during contraction refers to stroke volume, and the volume of blood during the systolic phase pertains to blood movement as the heart contracts rather than the amount present before contraction.