🏥 USMLE Exam Prep

In a cardiac pressure-volume loop, an increase in afterload, assuming constant contractility and preload, would result in which of the following changes?

A Decreased end-systolic volume (ESV)
B Increased stroke volume (SV)
C Increased end-diastolic volume (EDV)
D Increased isovolumic contraction time

✓ Correct Answer: Option D

Increased afterload means the ventricle must generate higher pressure to eject blood. This leads to a longer isovolumic contraction period to reach the higher aortic pressure, reducing the ejection fraction, increasing ESV, and decreasing SV.

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