Starling's curve

Starling's curve illustrates how the strength of the heart's contractions (stroke volume) varies with the amount of blood filling the heart (preload) before it contracts. As preload increases, the heart initially pumps more forcefully, improving blood output. However, beyond a certain point, too much filling stretches the heart excessively, leading to weaker contractions. This creates a curve that rises and then falls, showing an optimal filling level for maximum efficiency. Essentially, the heart's ability to pump effectively depends on balanced filling, with both too little and too much filling impairing performance.