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

The correct answer to the question "In a cardiac pressure-volume loop, an increase in afterload, assuming constant contractility and preload, would result in which of the following changes?" is Option D: Increased isovolumic contraction time.

The other options — A) Decreased end-systolic volume (ESV), B) Increased stroke volume (SV), C) Increased end-diastolic volume (EDV) — are incorrect for this USMLE Exam Prep question. As explained above: 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 f…