Related Experiment Video
Updated: May 30, 2026

Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance
Published on: March 21, 2013
Prolonged post-faint hypotension can be reversed by dynamic tension
W Wieling1, J Rozenberg, I K Schon
1Department of Medicine, Academic Medical Centre, University of Amsterdam,The Netherlands. w.wieling@amc.nl
Abstract:
A severe variant of vasovagal syncope, observed during tilt tests and blood donation has recently been termed "prolonged post-faint hypotension" (PPFH). A 49-year-old male with a life-long history of severe fainting attacks underwent head-up tilt for 20 min, and developed syncope 2 min after nitroglycerine spray. He was unconscious for 40 s and asystolic for 22 s. For the first 2 min of recovery, BP and HR remained low (65/45 mmHg and 40 beats/min) despite passive leg-raising. Blood pressure (and symptoms) only improved following active bilateral leg flexion and extension ("dynamic tension"). During PPFH, when vagal activity is extreme, patients may require central stimulation as well as correction of venous return.
Related Concept Videos
Alterations in Blood Pressure
Hypertension (High blood pressure)
Hypertension occurs when blood pressure readings consistently exceed the normal range. It is diagnosed when systolic blood pressure (the top number, indicating pressure while the heart beats)...
Cardiopulmonary Resuscitation IV: Pharmacological Management
Cardiac Catheterization IV: Nursing Management
Blood Pressure Imbalances and Circulatory Shock
Blood Pressure: Hypertension and Hypotension
Normal blood pressure is 120/80 mm Hg. Elevated blood pressure is 120-129/under 80 mm Hg. Hypertension, warranting treatment at 130/80 mm Hg, is often asymptomatic and can lead to severe cardiovascular events, aneurysms, peripheral arterial disease, chronic renal disease, or cardiac...
Heart Failure V: Medical Management
Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.

