Relationship between pulse pressure variation and preload

Pulse pressure variation (PPV) is a marker of the position on the Frank-Starling curve, not an indicator of blood volume or a marker of cardiac preload. Increasing preload induces a decrease in PPV (from 2 to 3). PPV is minimal when the heart is operating on the plateau of the Frank-Starling curve (3 and 4). Decreasing preload induces an increase in PPV (from 2 to 1), also increasing contractility (from 4 to 2).