Continuous ambulatory monitoring of blood pressure and assessment of cardiovascular reflexes in the elderly hypertensive.

Thirteen elderly hypertensives underwent continuous ambulatory blood pressure (BP) monitoring and measurement of cardiovascular reflexes. The results were compared with elderly normotensives and young hypertensives studied using the same protocol. There was a greater disparity between casual systolic BP (SBP) and ambulatory awake SBP in the elderly hypertensives than either the elderly normotensives or young hypertensives. Variability of SBP was greater in the elderly than the young, whilst baroreflex activity was reduced in the elderly, and more markedly so in the elderly hypertensives. Response to tilt and pressor tests was similar for the elderly. The elderly hypertensives showed a greater fall of SBP in response to tilt and a greater rise of SBP during dynamic exercise than the young hypertensives. Stimulation of plasma renin activity (PRA) in response to upright tilt was less in the elderly hypertensives than the young hypertensives. Resting plasma noradrenaline (PNA) increased with age.