CARDIOVASCULAR REACTIVITY IN ISOMETRIC-EXERCISE AND MENTAL ARITHMETICIN CHILDREN

In children, we studied noninvasively the cardiovascular stress respon ses, including changes over time of systolic blood pressure (SBP), hea rt rate (HR), and stroke volume (SV) in isometric handgrip (IHG) and m ental arithmetic. Specifically, we asked whether 1) these cardiovascul ar stress responses were different for the two stress conditions in ch ildren, 2) these responses differed in boys and girls, and 3) the anth ropometric variables related to these stress responses. SV differed si gnificantly between IHG and mental arithmetic over the entire stress p eriod. This may reflect higher systemic vascular resistance during IHG . HR in boys was lower than in girls over the entire period of stress in both stress tests. This observation cannot be attributed to differe nces in conditioning, because this should not influence responses to i sometric or mental stress. A larger left ventricular mass was related to higher SVs. A marked relationship was found between HR and SBP and between HR and SV. No relationship was found between SBP and SV.