Related Experiment Video
Updated: May 29, 2026
Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance
Published on: March 21, 2013
Reduced baroreflex sensitivity in situational syncope compared with vasovagal syncope: Evidence for different
Vincenzo Russo1, Erika Parente1, Angelo Comune1
1Cardiology Unit, University of Campania "Luigi Vanvitelli" - Ospedale Monaldi, Naples, Italy.
Background:
Baroreflex sensitivity (BRS) reflects short-term cardiovascular autonomic regulation and contributes to blood pressure stability, a key determinant of cerebral perfusion. We aimed to assess BRS in patients with situational syncope (SS) and to compare it with that of patients with vasovagal syncope (VVS) under standardized conditions.
Methods And Results:
We prospectively evaluated consecutive patients with suspected reflex syncope. Patients with confirmed SS or VVS and available BRS assessment at rest and during early orthostatic phase were included. The nearest neighbor propensity score matching (PSM) method with a 1:1 ratio was applied to balance baseline characteristics. Among 182 patients, 45 with SS were matched to 45 with VVS. Compared with VVS, SS patients exhibited significantly lower BRS both in the supine position (5.8±2.5 vs 7.4±4.0 ms/mmHg; p=0.02) and during orthostatic stress (5.3±2.7 vs 6.8±3.4 ms/mmHg; p=0.02). No differences in BRS were observed across different situational triggers.
Conclusions:
Situational syncope is associated with reduced baroreflex sensitivity compared with vasovagal syncope, supporting the presence of distinct baroreflex profiles within reflex syncope. These findings may have implications for pathophysiological classification and personalized management strategies.
Related Concept Videos
01:18Neural Regulation of Blood Pressure
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...
01:17Measurement of Blood Pressure
01:18Disorders of the Autonomic Nervous System
Raynaud's disease, also known as Raynaud's phenomenon, is a...
01:27Regulation of the Cardiovascular System
The regulation of the cardiovascular system involves the autonomic nervous system (ANS), baroreceptors, and chemoreceptors, ensuring that heart rate and blood pressure are appropriately modulated in response to varying physiological demands.
The ANS comprises two main divisions: the sympathetic and parasympathetic nervous systems. The sympathetic nervous system enhances...
01:30Alterations 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)...
01:24Blood 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...