The pathogenesis of vasovagal syncope has remained elusive despite many efforts to identify an underlying dysfunction. Catastrophe theory explains the spontaneous occurrence of sudden events in some mathematically complex systems known as self-organized systems poised at criticality. These systems universally exhibit a power law initially described in earthquake occurrence: the Gutenberg Richte...

We believe that the pattern of blood pressure response to tilt during the time preceding the development of the vasovagal reaction may provide adjunctive diagnostic information. A group of 101 consecutive patients affected by syncope of uncertain origin underwent passive tilt testing for 45 min at 60 followed, if negative, by oral (sublingual) trinitroglycerin (TNG) 0·4 g with continuation of t...

Vasovagal syncope is a significant medical problem without effective therapy, postulated to be related to a collapse of baroreflex function. While some studies have shown that repeated static tilts can block vasovagal syncope, this was not found in other studies. Using anesthetized, male Long-Evans rats that were highly susceptible to generation of vasovagal responses, we found that repeated ac...

BACKGROUND Though vasovagal syncope probably does not directly cause death, it is often associated with severe trauma and, when recurrent, significantly impairs the patient's quality of life. While drug therapy for vasovagal syncope is still controversial, recently two randomized studies revealed the efficacy of dual-chamber pacemaker implantation in decreasing recurrences in very symptomatic p...

OBJECTIVES We sought to determine whether there are age-related differences in vasovagal syncope. BACKGROUND In those with suspected vasovagal (neurocardiogenic) syncope, tilt testing demonstrates different hemodynamic responses. These responses may be age related, reflecting differing underlying pathophysiology. METHODS Using a two-stage tilt protocol with glyceryl trinitrate (GTN) provoca...

In normal children, any procedure that increases heart rate, such as the tilt test, may shorten the QT interval. The effect of the tilt test on QT interval in children with syncope remains unknown. We analyzed the response of RR and QT intervals during a tilt test in 3 groups of children: 28 healthy children (group 1), 26 with syncope of unknown etiology and negative tilt test results (group 2)...

The encouraging results from the "Inotropy Controlled Pacing in Vasovagal Syncope" (INVASY) Italian multicenter clinical trial – which demonstrated the effectiveness of pacing based on Closed Loop Stimulation (CLS, Biotronik, Germany) in preventing vasovagal syncope (VVS) [1,2] – provided us incentive to prepare a review entitled "Malignant Vasovagal Syncope." The review provides an updated rev...

OBJECTIVES In this study, we assessed the effectiveness of physical counterpressure maneuvers (PCM) in daily life. BACKGROUND There is presently no evidence-based therapy for vasovagal syncope. Current treatment consists of explanation and life-style advice. Physical counterpressure maneuvers have been shown to raise blood pressure and to control or abort vasovagal episodes in laboratory condit...