After-load correlates to ?

After-load correlates to ?

• A. Vascular Resistance
• B. Heart rate
• C. Preload
• D. Contractility

Answer: (A)

After-load is the pressure the ventricle must overcome to eject blood during systole. This load mainly comes from the systemic vascular resistance—the resistance the arterial system presents. When vascular resistance (and arterial pressure) increases, the ventricle has to generate higher pressure to open the aortic valve, raising after-load. Heart rate changes cardiac output but not the load the ventricle must push against; preload is the filling pressure/volume before contraction; contractility is the heart’s pumping strength. So systemic vascular resistance best describes after-load.

After-load is the pressure the ventricle must overcome to eject blood during systole. This load mainly comes from the systemic vascular resistance—the resistance the arterial system presents. When vascular resistance (and arterial pressure) increases, the ventricle has to generate higher pressure to open the aortic valve, raising after-load. Heart rate changes cardiac output but not the load the ventricle must push against; preload is the filling pressure/volume before contraction; contractility is the heart’s pumping strength. So systemic vascular resistance best describes after-load.