How is the stroke volume typically calculated in echocardiography?

The stroke volume is determined by the difference between end-diastolic volume (EDV) and end-systolic volume (ESV). During the cardiac cycle, the heart fills with blood during diastole (end-diastolic volume) and then ejects blood during systole (end-systolic volume). Stroke volume is essentially the amount of blood pumped out of the heart with each beat, and it represents the volume of blood that remains in the ventricle after contraction.

By calculating the stroke volume as EDV minus ESV, clinicians can assess the heart's efficiency and performance. This measurement is crucial for evaluating cardiac function and diagnosing various heart conditions, such as heart failure or valvular heart disease.

The other options do not accurately represent how stroke volume is calculated. The sum of end-systolic volume and end-diastolic volume does not yield stroke volume, as they are two endpoints of the cardiac cycle rather than a measure of ejected volume. Comparing atrial volumes does not relate to stroke volume, and dividing cardiac output by heart rate provides the average stroke volume but is not the method for calculating it directly.