This report evaluated (a) the temporal stability of hemodynamic
responses to three tasks using impedance cardiography, and (b)
the influence of aging on stress responses in a multi-ethnic
pediatric sample. One hundred children 8 to 10 years old and
49 adolescents 15 to 17 years old were tested at study entry
and on average 3 years later. Results showed that the composite
task-induced changes in stroke volume (SV), cardiac output (CO),
total peripheral resistance (TPR), and pre-ejection period (PEP)
were moderately stable across 3 years (rs = .36 to
.51), with children showing greater stability in task-induced
CO change than did adolescents. However, the magnitude of the
participant's stress responses changed over time, varied
by task, age group, and gender. These results suggest that
hemodynamic responses to stress change with aging during childhood
and adolescence and that they can be measured reliably.