This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiac Cycle, Subject name: Physiology
Left ventricular (LV) pressure-volume loop is shown below. During exercise within physiological limits, what is the effect on end-systolic volume? 
Select and explain. 
A. ESV decreases, B. ESV increases, C. ESV remains unchanged, D. ESV first decreases then increases
A: ESV decreases
Answer: A: ESV decreases 
Explanation: - There is increased sympathetic discharge that has a positive inotropic effect on the hea. - LV contractility increases, ejecting a greater stroke volume (SV). - Hence, there is decrease in ESV, as shown in the image.