In patients with arterial hypotension norepinephrine increased end-systolic ventricular elastance and arterial elastance. The effects of norepinephrine on stroke volume depend on baseline ventriculo-arterial coupling.

Although norepinephrine infusion corrects arterial hypotension in all subjects, increase of stroke volume occurred only in subjects with altered ventriculo-arterial coupling.

Arterial pressure, stroke volume index, cardiac index, indexed total peripheral resistance, arterial compliance, arterial elastance, and end-systolic ventricular elastance, were measured before and after norepinephrine infusion.

We estimated ventriculo-arterial coupling by the arterial elastance to end-systolic ventricular elastance ratio and defined stroke volume responders by a stroke volume increase greater than or equal to 15%.

22 of the 28 subjects had altered ventriculo-arterial coupling.

28 postoperative cardiac surgery patients, in whom physicians decided to administer norepinephrine infusion, were included.

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