Fig. 4

The ‘Doppler Starling curve’. The ‘normal’ and ‘abnormal’ curves represent extremes of cardiac function. A patient 1 begins in quadrant 3 with jugular Doppler spectrogram consistent with low central venous pressure; there is also low ccFT (baseline). With passive leg raise (PLR), the jugular spectrogram changes with rising central venous pressure, but ccFT falls. B patient 2 begins in quadrant 1 (baseline₁); the first rapid fluid challenge (RFC₁) changes both jugular venous and carotid arterial spectrograms in a manner consistent with rising central venous pressure and stroke volume, respectively. Baseline₂ and RFC₂ show the effects of the second fluid challenge