ORTHOSTATIC INTOLERANCE IN AUTONOMIC NEUROPATHIES & POSTURAL TACHYCARDIA SYNDROME

神经源性直立性低血压的发病机制和治疗 姿势性心动过速综合征（POTS）的认识还很有限。 最近 研究表明POTS是异质性的， 可能是有效的。 这些包括直立性的性别特异性 不耐受，限制性自主神经病变，血容量不足，静脉 合并，α和β受体异常和改变， 脑干机制，包括干扰中枢压力反射调节。 我们将对POTS和井进行详细的比较研究- 明确的进行性自主神经紊乱（多系统萎缩[MSA]， 单纯自主神经衰竭（PAF）和自主神经病。 研究 研究将包括全面的临床和实验室自主 使用问卷调查，Finapres的非侵入性技术和 阻抗体积描记法，输注血管活性剂，以评估 α和β受体的敏感性和压力感受器反射， 频谱分析，旨在更好地定义潜在的 立位不耐受的机制。 我们已经聚集了一大批 患者的POTS，并将能够确定其自然史。 从这些研究中获得的见解将用于改善管理 包括急性实验室给药， 提供了机制的见解，并具有治疗潜力。 疗效 提高POTS患者立位耐力的物理对抗措施将 被评价。 我们将确定是否直立不耐受的 正常妇女和POTS患者的年龄取决于 月经周期，并将试图确定是否中央调节 POTS患者的自主神经功能受损。

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.