Which condition would most directly increase right ventricular afterload?

Which condition would most directly increase right ventricular afterload?

• A. Decreased pulmonary vascular resistance
• B. Decreased systemic vascular resistance
• C. Increased pulmonary vascular resistance
• D. Increased left atrial pressure without pulmonary edema

Answer: (C)

Right ventricular afterload comes from the pressure the RV must generate to eject blood into the pulmonary circulation. It is set mainly by the pulmonary vascular resistance and the pressure in the pulmonary arteries. When pulmonary vascular resistance rises—such as in pulmonary hypertension or hypoxic vasoconstriction—the RV has to push against a higher resistance to move blood forward. This directly increases afterload on the right ventricle and can lead to RV strain or failure if it persists. Lowering pulmonary vascular resistance would ease the RV’s workload, so it would decrease afterload. Systemic vascular resistance affects the left ventricle because it pumps into the systemic circuit, not the pulmonary circuit. Elevating left atrial pressure increases pressures on the left side and pulmonary veins; unless it markedly raises pulmonary vascular resistance, it does not directly increase the RV’s afterload.

Right ventricular afterload comes from the pressure the RV must generate to eject blood into the pulmonary circulation. It is set mainly by the pulmonary vascular resistance and the pressure in the pulmonary arteries. When pulmonary vascular resistance rises—such as in pulmonary hypertension or hypoxic vasoconstriction—the RV has to push against a higher resistance to move blood forward. This directly increases afterload on the right ventricle and can lead to RV strain or failure if it persists.

Lowering pulmonary vascular resistance would ease the RV’s workload, so it would decrease afterload. Systemic vascular resistance affects the left ventricle because it pumps into the systemic circuit, not the pulmonary circuit. Elevating left atrial pressure increases pressures on the left side and pulmonary veins; unless it markedly raises pulmonary vascular resistance, it does not directly increase the RV’s afterload.