A cardiac valve experiences the highest pressure change during systole?

• A. Tricuspid valve
• B. Aortic valve
• C. Pulmonary valve
• D. Mitral valve

Answer: (B)

During systole the left ventricle contracts to push blood into the aorta, so the valve between the left ventricle and the aorta has to withstand a large pressure difference as blood is ejected into the high‑pressure systemic circulation. The systemic arterial system operates at much higher pressures than the pulmonary circuit or the right heart, so the transvalvular pressure change across the aortic valve is the greatest. The right‑sided valves (tricuspid and pulmonary) handle much lower pressures, and the mitral valve sits between the left atrium and ventricle; while there is a pressure difference there, the main flow during systole is through the aortic valve into the high‑pressure systemic circuit. Hence, the aortic valve experiences the highest pressure change during systole.