Abstract

Blood pressure, heart rate, and echocardiographic parameters of left ventricular size and shortening were measured both under baseline conditions and during handgrip exercise (50% maximum handgrip effort held to fatigue) in 20 normal women (20 through 29 years of age). As a group, there was a significant increase in heart rate (72 ± 10 vs 83 ± 12; P < .001), systolic blood pressure (111 ± 8 vs 133 ± 14 mm Hg; P < .001), diastolic blood pressure (67 ± 8 vs 89 ± 12 mm Hg; P < .001), and calculated cardiac output (4.3 ± 1.5 vs 5.2 ± 1.7 liters/minute; P < .005). There was no significant change in left ventricular internal dimension in diastole or systole, shortening fraction, or calculated stroke volume. The average group response of ah increase in cardiac output secondary to an increase in heart rate is similar to that of male subjects in their second decade. Individual variability in responses was of specific interest since only three of the 20 women demonstrated a totally characteristic response to handgrip exercise. Handgrip exercise in young women may not provide a uniformly characteristic response from which to predict hemodynamic changes in a given individual and may lead to clinical misinterpretation if appropriate caution is not used.