Pressure volume loop. A representative depiction of the pressure-volume relationship comparing the slope of the end-systolic pressure-volume relationship (ESPVR) and the slope of the line joining the ESP and EDV points (EA) from a healthy young control (A) and an older individual with hypertension (B). End-systolic elastance (ELV) reflects a load-independent measure of left ventricular (LV) contraction, and is steeper in an older hypertensive individual. Effective arterial elastance (EA), a measure of net arterial load on the LV, is increased (thereby reducing SV and increasing ESP) in an older individual compared to a young healthy individual. Vo represents the theoretical volume intercept of the ESPVR; ESP, end systolic pressure; SV, stroke volume; ESV, end systolic volume; EDV, end diastolic volume; and EDPVR, end diastolic pressure volume relationship.