SOURCE: McJunkin B, et al. Detecting initial orthostatic hypotension: A novel approach. J Am Soc Hypertens 2015;9:365-369.
Orthostatic hypotension (OH) is typically defined as a decline in blood pressure (BP) > 20/10 mmHg within 3 minutes of standing. OH is consequential not only because of adverse symptoms, such as dizziness, blurred vision, or so-called “coat-hanger” headache, but also because it is associated with falls. Fall risk leads to life-changing consequences, such as hip fracture and loss of autonomy due to non-independent living.
A less familiar form of orthostasis is termed initial orthostatic hypotension (IOH). IOH is characterized by a dramatic decline in BP (> 40/20 mmHg) presenting within the first 15 seconds of standing, which self corrects within 30-60 seconds. IOH differs from the normal physiologic experience many of us have had of a transient decrease in BP, which recovers by 30 seconds. IOH, then, is a prolongation of recovery time, during which patients might experience hypotensive symptoms or even falls.
One of the limitations of prior investigations about IOH has been the delay in BP measurement incurred by simply using 5-10 seconds or more to inflate the BP cuff to measure the BP in the first place! McJunkin et al suggest that this obstacle can be obviated by fully inflating the cuff while a patient is supine, allowing immediate deflation and BP measurement upon standing.
Among a population of elderly patients (n = 115), 12% were found to have OH, and 3.5% to have IOH. IOH represents a population at risk for falls, which may be missed with “traditional” methods of orthostatic BP measurement.