Cardiovascular responses to isometric handgrip exercise: an invasive study in pregnancy-induced hypertension

Nine patients with pregnancy-induced hypertension and nine healthy pregnant controls were compared in the last trimester with regard to cardiovascular and sympathoadrenal reactivity during a standardized isometric handgrip exercise test. At rest, the blood pressure elevation with pregnancy-induced hypertension resulted from increased systemic vascular resistance. The test increased the blood pressure, heart rate, cardiac output, stroke volume, and epinephrine and norepinephrine concentrations in arterial plasma, but did not change the calf or systemic vascular resistance. The responses of the two groups did not differ significantly with regard to any of the above variables. Thus, pregnancy-induced hypertension does not seem to be associated with exaggerated cardiovascular or sympathoadrenal reactivity to isometric exercise when compared with normal pregnancy. The mechanism underlying the blood pressure response appears to be similar in the two groups, ie, an increase in cardiac output.