Figure 3. Cardiac output, stroke volume and systemic vascular resistance at baseline and in response to intravenous terbutaline before (left panel) and after (right panel) dietary sodium restriction in Gly16 and Arg16 subjects.

In the Gly16 group, dietary sodium restriction significantly decreased baseline cardiac output (CO, **P = 0.003), tended to decrease stroke volume (SV, †P = 0.06) and increased systemic vascular resistance (SVR, *P = 0.02), whereas these baseline indices were unaffected in the Arg16 group. Terbutaline increased CO and SV, and decreased SVR (P < 0.001), but there were no differences in the responses to terbutaline based on diet or genotype. Error bars denote s.d.