Which statement describes the effect of decreased afterload on arterial pressure and LV work?

• A. Decreased afterload lowers arterial pressure and makes LV work more easily
• B. Decreased afterload raises LV end-diastolic volume
• C. Increased afterload reduces LV stroke volume
• D. Afterload has no effect on LV workload

Answer: (A)

Afterload is the pressure the left ventricle must overcome to eject blood into the aorta. When afterload decreases, the ventricle faces less resistance, so it can generate a lower systolic pressure to push the same amount of blood outward. This reduces the ventricular wall stress and the pressure–volume work the heart must perform each beat, meaning LV work decreases. With less pressure opposing ejection, systolic arterial pressure tends to fall as well, reflecting the reduced driving pressure the heart must produce. This makes the heart’s pumping effort easier, which is the core reason the statement is correct. The effect on preload (end-diastolic volume) is less direct, and while very high afterload can reduce stroke volume, lowering afterload does not describe that situation. Saying afterload has no effect on LV workload is incorrect because workload is directly tied to the pressure the ventricle must generate.