End-systolic volume (ESV) and end-diastolic volume (EDV) are key parameters in the analysis of left ventricular (LV) function, and the study of cardiac remodeling. The volume regulation graph (VRG) relates these fundamental determinants, and permits convenient stratification for clinically relevant covariates. This contribution analyzes sex-associated differences in hemodynamic parameters for 197 heart failure (HF) patients, evaluated by biplane ventriculography, in combination with arterial pressure. We calculated LV parameters such as stroke volume (SV), cardiac output (CO), ESV, EDV, ejection fraction (EF), end-systolic elastance (Emax), besides arterial parameters: effective arterial elastance (Ea), elastance ratio (the coupling index k), peripheral resistance (Rs), pulse pressure (PP), and arterial compliance (C), all normalized for body surface area when appropriate. Average values for heart rate, SV, CO, Ea, C, Rs are similar between the sexes, as are the VRG regression lines. However, ESV and EDV are significantly (P<0.034 and P<0.016, respectively) smaller in women (N=67), whereas EF, Emax, mean arterial pressure, PP, and k are higher (P<0.008 or less). We conclude that the various sex-associated differences observed in these HF patients are striking, and thus require due attention when evaluating the clinical status of HF patients. Formulation of distinct cut-off values for male and female patients with HF seems warranted, when considering specific HF phenotypes.