Spectrum of Hemodynamic Responses in the First 60 Seconds after Active Standing Up: Importance of Time Course of Blood Pressure Changes and Definitions

The study by Doyle et al corroborates earlier findings in The Irish Longitudinal Study on Ageing (TILDA) cohort that a delayed recovery of blood pressure (BP) in the first 60 seconds after active standing up is associated with injurious falls in community-dwelling older people. Given the serious outcome associated with injurious falls (especially hip fractures), identification of delayed recovery of BP after standing up as a potentially modifiable risk factor is important and highly relevant. In the assessment of falls and syncope in older people, continuous noninvasive monitoring of finger arterial pressures in the first 60 seconds after active standing up has emerged as an important clinical tool. ^{,  ,  ,}  To compare the important findings in the present study and future work standardization of terminology to classify the spectrum of orthostatic responses in the first 60 seconds after the onset of active standing up is pertinent. ^, The Consensus of the American Autonomic Society defines classical orthostatic hypotension as a sustained reduction of systolic BP of at least 20 mm Hg and/or diastolic BP of 10 mm Hg within 3 minutes of standing or head-up tilt 60°. In 2011, the American Autonomic Society Consensus statement was expanded to include initial orthostatic hypotension [ie, a transient BP decrease (≥40 mm Hg systolic BP and/or ≥20 mm Hg diastolic BP within 15 seconds of active standing)]. In the TILDA population studies, it became clear that delayed recovery of BP often occurs in older individuals. ^,, To classify these responses, a delayed BP recovery pattern was defined as a fall in systolic BP ≥20 mm Hg at 30‒40 seconds after standing up, but not meeting the criteria of classical orthostatic hypotension with sustained hypotension (fall in systolic BP ≥20 mm Hg after 1‒3 minutes standing). ^,,, In clinical practice, usually only the systolic BP cut-off is used to diagnose classical orthostatic hypotension or initial orthostatic hypotension.