ORTHOSTATIC INTOLERANCE IN AUTONOMIC NEUROPATHIES & POSTURAL TACHYCARDIA SYNDROME

神经源性直立性低血压的发病机制及处理 体位性心动过速综合征(POTS)知之甚少。近期 研究表明，POTS是异质性的，并且有许多机制 可能在行动中。这些因素包括直立位的性别特异性 不耐受，局限性自主神经病变，血容量减少，静脉 合并、α和β受体异常和改变 脑干机制，包括紊乱的中枢压力感受性反射调节。 我们将对盆和井进行详细的比较研究- 明确的进行性自主神经障碍(多系统萎缩[MSA]， 纯自主神经衰竭(PAF)和自主神经病变。这项研究 研究将包括全面的临床和实验室自主神经 应用问卷、Finapres非侵入性技术和 阻抗体积描记术、血管活性物质输注的评价 α和β受体的敏感性和压力感受器再次反射，以及力量 光谱分析，以这种方式设计，以更好地定义潜在的 直立不耐受的机制。我们已经积累了一大批人 并将能够定义其自然病史。 从这些研究中获得的见解将被用来改善管理 包括急性实验室给药，可以 提供机械洞察力，并具有治疗潜力。药效 在POTS意志中提高立位耐力的物理反操作 被评估。我们将确定是否存在直立不耐受 正常女性和有盆栽的女性依赖于 并将试图确定月经周期的中枢调节是否 POTS患者自主神经功能受损。

The pathogenesis and management of neurogenic orthostatic hypotension and the postural tachycardia syndrome (POTS) are poorly understood. Recent studies suggest that POTS is heterogenous and that a number of mechanisms might be operative. These include gender-specificity of orthostatic intolerance, a restricted autonomic neuropathy, hypovolemia, venous pooling, alpha- and beta-receptor abnormalities and alterations in brainstem mechanisms, including perturbed central baroreflex regulation. We will undertake a detailed comparative study of POTS with the well- defined progressive autonomic disorders (multiple system atrophy [MSA}, pure autonomic failure (PAF} and the autonomic neuropathies). The research studies will consist of comprehensive clinical and laboratory autonomic studies using questionnaires, non-invasive techniques of Finapres and impedance plethysmography, infusions of vasoactive agents to evaluate alpha- and beta-receptor sensitivity and baroreflex again, and power spectral analysis, designed in such a way to better define the underlying mechanisms of orthostatic intolerance. We have accumulated a large cohort of patients with POTS and will be able to define its natural history. Insights gained from these studies will be used to improve the management of POTS, including the acute laboratory administration of agents that can provide mechanistic insights and have therapeutic potential. The efficacy of physical countermaneuvers to improve orthostatic tolerance in POTS will be evaluated. We will determine whether the orthostatic intolerance of normal women and those with POTS are dependent on the phase of the menstrual cycle and will attempt to determine whether central regulation of autonomic function is impaired in POTS.