Key Points
- To identify the physiological, hormonal, and demographic factors that determine beat-by-beat arterial pressure variability in patients with essential hypertension.
- Continuous intra-arterial blood pressure was recorded beat by beat and analyzed by computer under standardized conditions in 26 patients with uncomplicated essential hypertension.
- Pressure variability was calculated as the standard deviation of normally distributed frequency histograms across states of sleep, bed rest, and ambulation.
- Blood pressure variability was lowest during sleep and increased progressively with bed rest and daytime ambulation, independent of the time of day.
- Systolic variability correlated directly with absolute systolic pressure and had an independent inverse relationship with baroreflex sensitivity, with a positive trend linked to obesity.
- No independent associations with variability were found for age, race, sex, plasma renin activity, plasma angiotensin II, plasma noradrenaline, or plasma adrenaline.
Structured PICO
PPopulation26 patients with uncomplicated essential hypertension
OOutcomeVariability of arterial pressure (measured as the standard deviation of the normally distributed frequency histogram)surrogate
Arterial pressure variability in essential hypertension is primarily driven by physical activity, absolute systolic pressure, and baroreflex sensitivity, rather than neurohormonal factors.