Orthostatic hypotension – classical, delayed and initial

Orthostatic hypotension – classical, delayed and initial

Orthostatic hypotension (OH) has been divided into classical, delayed and initial.

Classical OH is sustained fall in systolic blood pressure of  at least 20 mm Hg or diastolic blood pressure of  10 mm Hg within three minutes of standing or head up tilt test. Compensatory tachycardia may be seen, but can be absent in case of autonomic failure [1].

Delayed OH  sustained fall in blood pressure after 3 minutes of standing or head up tilt test. Half of them can progress to classical OH in the long run in a 10 year follow up study [2].

Initial OH is defined as a fall in systolic blood pressure of at least 40 mm Hg and/or fall in diastolic blood pressure of at least 20 mm Hg within 15 seconds of standing with symptoms of cerebral hypoperfusion [3]. It is more common in younger patients, but may also occur in the elderly [1]. It occurs mostly on active standing than passive tilt table testing and is thought to be due to marked fall in peripheral vascular resistance leading to a mismatch between cardiac output and peripheral resistance. As it is transient, only beat to beat blood pressure monitoring during active standing can document this condition.

References

1. Freeman R, Abuzinadah AR, Gibbons C, Jones P, Miglis MG, Sinn DI. Orthostatic Hypotension: JACC State-of-the-Art Review. J Am Coll Cardiol. 2018 Sep 11;72(11):1294-1309.
2. Gibbons CH, Freeman R. Clinical implications of delayed orthostatic hypotension: A 10-year follow-up study. Neurology. 2015 Oct 20;85(16):1362-7.
3. Wieling W, Krediet CT, van Dijk N, Linzer M, Tschakovsky ME. Initial orthostatic hypotension: review of a forgotten condition. Clin Sci (Lond). 2007 Feb;112(3):157-65.