[Mitral valve prolapse syndrome: orthostatic hypotension and physiopathology of its clinical symptomathologies].

Although several investigations on mitral valve prolapse syndrome (MVPS) have been performed, clinical symptoms of this syndrome are not yet clarified. Atypical chest pain, palpitations, fatigue, dyspnea and anxiety are the most frequent symptoms associated with this syndrome. However, dizziness and syncope may be serious symptoms in MVPS. Dizziness and syncope are related to cardiac arrhythmias and are proposed to distinguish types, frequency of arrhythmias and relation to the symptoms. Orthostatic hypotension and tachycardia rarely occur in MVPS. The physiopathological mechanisms of these symptoms are not known clearly, but multifactorial causes are thought to be responsible including autonomic dysfunction, hyperadrenergic state, abnormalities in regulation of baroreceptors, parasympathetic derangements, decrease of intravascular volume, abnormal renin-aldosterone response to depletion of intravascular volume and abnormal release of atrial natriuretic factor.