Circadian blood pressure overswinging in a physically fit, normotensive African American woman

Ambulatory blood pressure (BP) and heart rate (HR) were measured in a physically fit, normotensive postmenopausal African American woman, before and after 15 weeks of aerobic training. Mean BP, HR, and HR variability were normal at the outset and were further improved by training. Training had no effect on circadian BP variation, which exceeded gender- and age-specified limits, indicative of circadian hyperamplitude tension (CHAT). A 12-week treatment with the β1-adrenoceptor blocker atenolol, 14 months post-training, normalized CHAT and HR variability and further reduced BP and HR. These results suggest β1-adrenergic mediation of CHAT and its refractoriness to exercise training.