Sex differences in sepsis are underexplored, even though female sex appears to be cardioprotective in early sepsis.In early normovolaemic polymicrobial sepsis, hyperdynamic response occurs in males, whereas myocardial stress/injury is limited in females, in part mediated by less cardiac infiltration of CD4 + leukocytes and independent of shedding of TNFα from peripheral circulating leukocytes.