Should Orthostatic Changes in Blood Pressure be Measured After One or Three Minutes in Elderly Subjects?

Orthostatic hypotension is common in the elderly. Standard clinical practice is to measure changes in SBP after 1 minute or 3 minutes of upright posture. In an elderly patient, the lowest blood pressure may occur early after the assumption of upright posture and recover. To address this issue, we evaluated beat to beat changes in SBP and heart rate during the first 3 minutes of upright posture on a tilt table in a cohort of community-dwelling elderly subjects. Almost all of the subjects have significant declines in SBP with upright posture. While the majority of the transient hypotensive episodes are not detected by the standard clinical approach, measurement of SBP after 1 minute of upright posture was twice as sensitive as a single measurement at 3 minutes. Use of continuous beat to beat measurement of SBP identified an even greater number of elderly subjects who have transient orthostatic hypotension.