Fig. 1.

Starling curve and left ventricular function: the relationship between SV and preload. a If fluid challenge adequately improves SV, a patient is considered hypovolemic (responder). b If fluid was given at the plateau of Starling curve, SV will not increase, and a patient is considered normovolemic (non-responder). c For decreased left ventricular function cases, SV response after fluid loading cannot be observed even in hypovoelia, as Starling curve is flatter than the normal cardiac function cases. SV stroke volume