After repairing a ventricular septal defect with a prosthetic patch, which change in pressures best describes LV, RV, and LA pressures?

• A. LV pressure goes up; RV pressure goes down; LA pressure goes down
• B. LV pressure goes down; RV pressure goes up; LA pressure goes up
• C. LV pressure goes up; RV pressure goes up; LA pressure goes up
• D. LV pressure unchanged; RV pressure unchanged; LA pressure unchanged

Answer: (A)

Closing a ventricular septal defect removes the low-resistance shortcut from the left ventricle to the right ventricle, so the left ventricle now ejects solely into the high-resistance aorta. That increases the LV systolic pressure (afterload rises). The right ventricle no longer receives the high-pressure input from the LV, so its pressure falls. With less left-to-right shunting, pulmonary blood flow decreases, reducing returning flow to the left atrium and lowering left atrial pressure. This combination—LV pressure up, RV pressure down, LA pressure down—fits the post-repair hemodynamics best.