Ace Echocardiography Techniques III 2026 – Master the Heartbeat Challenge!

Conservation of flow in a closed circulatory system means the same amount of blood moves through the heart in each beat, provided valves are competent and there are no regurgitant flows or intracardiac shunts. In a normal heart, the volume ejected from the ventricle during systole through the outflow valve must match the volume that entered the ventricle during the prior filling through the inflow valve. The right and left sides also maintain equal stroke volumes in steady state. Because there is no leakage or diversion, the stroke volume remains the same through each valve for a given heartbeat, even though pressures and flows differ during different phases of the cycle. Variations due to respiration influence preload and beat-to-beat stroke volume, but the amount that moves through each valve in a single cycle remains the same when valves are competent.