טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentGazit Yael
SubjectHypermobility Syndrome: Autonomic Cardiovascular Profile
DepartmentDepartment of Medicine
Supervisors Clinical Professor Abraham Nahir
Mr. Giris Jacob


Abstract

Purpose: Dizziness and palpitaions described by patients with the hypermobility syndrome (HMS), where related in the past to mitral valve prolapse (MVP). As an increased prevalence of MVP among HMS patients was rejected, the purpose of this study was to investigate whether these symptoms relate to a possible autonomic nervous system (ANS) dysfunction (dysautonomia) among these patients.

Subjects and Methods: Forty eight HMS patients, who fulfilled the 1998 Brighton criteria, and 30 healthy control subjects answered a clinical questionnaire designed to evaluate the frequency of complaints related to the ANS. Then, 27 patients and 21 controls underwent autonomic evaluation: orthostatic test, cardiovascular vagal and sympathetic functions,  and adrenoreceptors responsiveness. 

Results: Symptoms related to the ANS, such as syncope and pre-syncope (dizziness, blurred vision etc.), palpitations, chest discomfort, fatigue and heat intolerance were significantly more common among patients. Heart rate rose  and systolic blood pressure (SBP) dropped significantly at 3 minutes upright. Dysautonomias, such as orthostatic hypotension, postural orthostatic tachycardia syndrome, and uncategorized orthostatic intolerance, were found in 78% of patients compared to 10% of controls. Sympathetic indices of patients showed a major drop in SBP during hyperventilation and a higher increase in SBP after cold pressor test. Also, patients presented a  and b adrenoreceptors hyper-responsiveness as assessed by administration of phenylephrine and isoproterenol, respectively.

Conclusion: Dysautonomia is common among HMS patients. The parasympathetic nervous system was intact in the presence of disturbed sympathetic nervous system and adrenoreceptors hyper-responsiveness.  These findings suggests that dysautonomia is part of the extraarticular manifestations of HMS.