background: syncope is a common clinical problem which can be remarkably debilitating and associated with high health care costs. syncope is a clinical syndrome with many potential causes. the aim of the study was to determine the etiologies of patients with syncope in the emergency department (ed) of a referral and general university hospital.  methods: one hundred sixty-five consecutive patie...

Thirteen healthy subjects were tested for parasympathetic reactivity during head-up tilt and reversal of the tilt. Head-up tilt (70 degrees) resulted in significant increase in baseline heart rate and diastolic blood pressure. Head-up tilt also led to increased parasympathetic reactivity as measured by Valsalva manoeuvre and hand grip test. Heart rate response to deep breathing test did not cha...