1 is an oversimplification in one import- ant respect. We have to start with what weve got, not least to ensure service continuity while we re-examine our methods. Patients with severe hypotension due to poor left ventricular performance after acute myocardial in- farction (cardiogenic shock) may not tolerate a rapid, large fluid bolus because the filling pressure of the left ventricle is already increased and its muscle fibres are overstretched.