How is Stroke Volume (SV) calculated?

Stroke Volume (SV) is an essential physiological parameter that represents the amount of blood pumped by the heart with each heartbeat. The calculation of SV is done by determining the difference between two critical measures of heart function: End-Diastolic Volume (EDV) and End-Systolic Volume (ESV).

EDV refers to the volume of blood in the ventricles at the end of filling (diastole), just before contraction. ESV, on the other hand, is the volume of blood left in the ventricles after contraction (systole). Therefore, to find the stroke volume, you subtract the ESV from the EDV. This subtraction gives you the volume of blood ejected from the heart during each contraction, which is exactly what stroke volume represents.

In summary, the formula for stroke volume is SV = EDV - ESV, making it clear why the correct answer is based on this calculation. Understanding SV is crucial in evaluating cardiac function and overall cardiovascular health, as it provides essential insights into how effectively the heart is performing its pumping action.