January 1, 1994
View Full PaperEffect of Age on the Hemodynamic Response to Posture in Nonelderly Hypertensive Patients
Key Result
Older age in hypertensive men was associated with less pronounced postural falls in cardiac output (P<0.001) and stroke volume (P<0.001), and a smaller increase in heart rate (P<0.01).
Study Design
Type
Cross-Sectional (n=110)
Structured PICO
Does age affect the hemodynamic response to a change in posture in nonelderly men with essential hypertension?
P
Population
110 men aged 16 to 64 years with essential hypertension and no cardiovascular complications, undergoing invasive hemodynamic measurements.
E
Exposure
Change in posture to sitting for 10 minutes
C
Comparator
Supine rest for 30 minutes
O
Outcome
Hemodynamic response (changes in intraarterial pressure, heart rate, systemic vascular resistance, cardiac output, stroke volume, and pulmonary capillary wedge pressure) and its relationship with agesurrogate
In nonelderly hypertensive men, older age is associated with smaller postural falls in cardiac output and stroke volume and a blunted heart rate increase, while peripheral vascular resistance control is preserved.
Main Result
p-value: p=<0.001
Abstract
The objective of this study was to assess the effects of age on the hemodynamic response to a change in posture in essential hypertension. Invasive hemodynamic measurements were performed in the supine and sitting position in 110 men, aged 16 to 64 years, in whom cardiovascular complications were virtually excluded. The change of systolic and diastolic intraarterial pressure, from 153/83 mm Hg after 30 min of supine rest to 156 (P .10) related to age. Heart rate (+9 beats/min) and systemic vascular resistance (+4.6 mm Hg/L/min) increased (P .10). The slopes of the postural changes of heart rate and of systemic vascular resistance differed significantly (P = .01). The results were not confounded by the level of blood pressure or weight. In conclusion, the smaller postural falls of cardiac output, stroke volume, and wedge pressure in older patients suggest less thoracic blood volume displacement to the lower parts of the body, possibly resulting from a lesser peripheral venous distensibility. The increase of heart rate in response to the upright posture is less pronounced at older age, whereas the reflex control of the peripheral vasculature is preserved and blood pressure maintained.