A patient-specific hemodyanmic status model is determined from impedance data collected during periods of normal and abnormal hemodynamic status by deriving parameter values of a set of multiple impedance-derivable parameters from impedance signals collected during periods of normal hemodynamic status and in connection with periods of abnormal hemodynamic status. The parameter values are employed to estimate coefficients of a linear parametric status model. These coefficients can then be used together with parameter values determined from impedance signals determined during status assessment periods in order to determine a current hemdoynamic status of the patient.