Norepinephrine (NE) is a potent vasopressor used in septic shock to reverse hypotension. Early infusion of NE was associated with a favorable clinical outcome in a large cohort of patients . When administered early, NE increases cardiac output (CO) in patients with septic shock . This effect was suggested to be mainly related to an increased cardiac preload via the α-adrenergic-mediated decrease in systemic venous capacitance . Whether NE exerts a positive effect on cardiac contractility through β1-adrenergic stimulation is unclear. On the one hand, the sensitivity of β1-adrenergic receptors can be abnormally reduced in septic conditions. On the other hand, such a sepsis-induced down-regulation of β1-adrenergic receptors may occur relatively late and thus, might not be observed when NE is administered early. Our study was designed to examine the inotropic effects of NE when administered in the early phase of human septic shock