The heart's pumping strength is referred to as?

• A. Cardiac Output
• B. Stroke Volume
• C. Myocardial Contractile Force
• D. Afterload

Answer: (C)

Pumping strength refers to how forcefully the heart muscle contracts to push blood out during systole. This is described by the myocardial contractile force, the intrinsic ability of cardiac muscle fibers to shorten and generate tension. Cardiac output, the total blood pumped per minute, comes from multiplying heart rate by stroke volume and doesn’t describe per-beat strength itself. Stroke volume is the amount ejected with each beat, influenced by contractility but not the measure of pumping strength on its own. Afterload is the pressure the heart must work against to eject blood, which affects how much blood is ejected but isn’t the contractile strength of the pump.