Venous return

What it is

Venous return is the blood flow returning from the systemic veins to the heart.^[1]

Why it matters

The heart can only pump what returns to it over time, so venous return is a major input-side constraint on cardiac output.^[1,2]

Root causes of abnormal values

• Return-flow relation: Venous return rises when more blood volume and venous tone push blood back toward the heart; it falls when circulating volume is low, venous pooling is high, or return is obstructed.^[1,3,2]
  Circulating blood volumeVascular tone / vasodilationCardiac preloadCardiac output

What it affects

• It connects circulating volume, venous tone, preload, stroke volume, and cardiac output.^[1,2]

Interpretation traps

• Venous return is a system-flow concept and usually requires clinical context to evaluate.^[1]

Related conditions