End-systolic pressure-volume relationship (ESPVR) is used to define which aspects of LV function?

• A. Preload
• B. Heart rate
• C. Afterload and contractility
• D. Venous return

Answer: (C)

End-systolic pressure-volume relationship shows how the left ventricle performs at the end of systole across different loading conditions. The slope of this relationship, called Emax, reflects how strongly the ventricle can contract—contractility. The position of the ESPVR is influenced by afterload, since a higher afterload means the ventricle must generate more pressure to eject blood, changing the end-systolic point. So ESPVR captures both afterload and contractility.

Preload and venous return mainly set the preload state (end-diastolic conditions) rather than the end-systolic mechanics, and heart rate affects timing rather than the steady-state end-systolic P–V relationship.