A patient has a an end diastolic volume of 125mL. A heart attack has weakened her left ventricle so it can pump a stroke volume of only 40mL. Calculate her end systolic volume.

The patient's end-systolic volume will be 85 mL

Explanation:

The end-systolic volume (ESV) is the amount of blood present in the ventricle at the end of a ventricular contraction or a systole and at the beginning of a diastole or ventricular expansion.

Throughout the cardiac cycle, the lowest blood volume will be the ESV.

ESV is a clinical cardiac marker and reflects function of the ventricular ejection or cardiac emptying and systolic function.

During a heart attack, the stroke volume will decrease due to inefficiency of the heart muscles to pump more blood.

Stroke volume (SV) is the total amount of blood that the heart pumps out from the ventricle with each heart beat

The end-diastolic volume (EDV) is the amount of blood at end of diastole and beginning of a systole.

The formula for calculating stroke volume SV = EDV-ESV

In the above case the SV is 40 mL and the EDV is 125 mL

Substituting in the above formula ESV = 85 mL