What is the described effect of aging on stroke volume?

What is the described effect of aging on stroke volume?

• A. It increases
• B. It remains constant
• C. It decreases due to increased afterload
• D. It fluctuates

Answer: (C)

Stroke volume changes with preload, afterload, and contractility. As people age, arteries stiffen and lose compliance, which raises afterload—the pressure the left ventricle must overcome to eject blood. When afterload is higher, the heart has to work harder to eject blood, and without a proportional rise in contractility, less blood is pushed out with each beat. This tends to reduce the amount of blood ejected per beat, so stroke volume decreases. While aging can also affect preload a bit, the heightened afterload from arterial stiffness is the primary reason stroke volume tends to decline.

Stroke volume changes with preload, afterload, and contractility. As people age, arteries stiffen and lose compliance, which raises afterload—the pressure the left ventricle must overcome to eject blood. When afterload is higher, the heart has to work harder to eject blood, and without a proportional rise in contractility, less blood is pushed out with each beat. This tends to reduce the amount of blood ejected per beat, so stroke volume decreases. While aging can also affect preload a bit, the heightened afterload from arterial stiffness is the primary reason stroke volume tends to decline.