In a patient with severe aortic stenosis, how is the left-ventricular pressure-volume loop typically altered?

• A. Decreased afterload with increased SV.
• B. Increased afterload; ESV rises, SV falls; loop shifts to higher end-systolic pressure with reduced width.
• C. No change in afterload; SV increases.
• D. Afterload decreases and the loop widens.

Answer: (B)

In severe aortic stenosis, the left ventricle faces much higher afterload because the aortic valve is narrowed. To open that valve, the ventricle must generate a much higher systolic pressure, so the end-systolic pressure in the ventricle rises. The heightened afterload also means the ventricle ejects less blood, so the end-systolic volume increases and the stroke volume falls. On the pressure-volume loop this shows up as a loop with a higher end-systolic pressure and a reduced width (smaller stroke volume). If there’s some rise in end-diastolic volume from diastolic changes due to hypertrophy, the loop might shift a bit, but the hallmark is increased afterload with higher ESP and NEV, and a decreased SV, producing a loop that sits higher on the pressure axis and is narrower.