Abstract: A method for determining haemodynamic performance in a human or animal subject comprises receiving at a processor data representing haemodynamic variables measured from the subject over time. The haemodynamic variables comprise at least two of Systemic Perfusion Pressure (SPP), Systemic Vascular Resistance (SVR), Cardiac Output (CO), Heart Rate (HR) and Stroke Volume (SV). The data are processed to produce a display signal for causing a display device to present a visual mapping relating the haemodynamic variables according to the relationship SPP=CO×SVR and the visual mapping is displayed on a display device. The visual mapping may be corrected Heart Rate (HR) or include a second mapping which facilitates an adjustment to take account of HR.