Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, USA.
Clin Auton Res. 2010 Apr;20(2):93-9. doi: 10.1007/s10286-009-0045-y. Epub 2009 Dec 25.
Postural tachycardia syndrome (POTS) is a heterogeneous disorder characterized by excessive orthostatic tachycardia in the absence of orthostatic hypotension and by sympathetic nervous system activation. Postganglionic sudomotor deficits have been used to define a neurogenic postural tachycardia POTS subtype. Norepinephrine levels above 600 pg/ml have also been used to delineate patients with a hyperadrenergic state. This study aims to determine the relationship of sudomotor abnormalities to other aspects of dysautonomia in POTS.
Autonomic function was quantified in thirty women through tests of cardiovagal, adrenergic, and sudomotor function including quantitative sudomotor axon reflex testing (QSART) and spectral indices. Differences between patients with and without sudomotor dysfunction as defined by QSART and between patients with and without hyperadrenergic POTS were assessed with Mann-Whitney U test and Mantel-Haenszel Chi-Square test using a p value of 0.01 for significance. Spearman correlation coefficients were used to test raw sweat volume correlations with other variables.
Of 30 women (ages 20-58), 17 patients (56%) had an abnormal QSART which was typically patchy and involved the lower extremity, while 13 patients had normal QSART results. Other autonomic tests, catecholamines or spectral indices did not correlate with QSART results. No differences in autonomic tests or spectral indices were observed between hyperadrenergic and non-hyperadrenergic POTS.
Our findings confirm that a large subset of POTS patients have sudomotor abnormalities which are typically patchy in distribution but do not correlate with other tests of autonomic function. Further studies are needed to determine the best method of endophenotyping patients with POTS.
体位性心动过速综合征（POTS）是一种异质性疾病，其特征为直立位时心动过速而无直立性低血压，并伴有交感神经系统激活。节后自主神经出汗功能障碍已被用于定义神经原性体位性心动过速 POTS 亚型。去甲肾上腺素水平高于 600pg/ml 也被用于描绘高肾上腺素能状态的患者。本研究旨在确定自主神经功能障碍与 POTS 中其他自主神经功能障碍方面的关系。
通过对心脏迷走神经、肾上腺素能和自主神经功能的测试，包括定量自主神经轴反射测试（QSART）和频谱指数，对 30 名女性的自主神经功能进行量化。使用 Mann-Whitney U 检验和 Mantel-Haenszel Chi-Square 检验，以 p 值为 0.01 作为显著性检验标准，评估 QSART 定义的有和无自主神经功能障碍的患者之间以及有和无高肾上腺素能 POTS 的患者之间的差异。使用 Spearman 相关系数检验原始汗液量与其他变量的相关性。
在 30 名女性（年龄 20-58 岁）中，17 名患者（56%）的 QSART 异常，通常为斑片状，涉及下肢，而 13 名患者的 QSART 结果正常。其他自主神经测试、儿茶酚胺或频谱指数与 QSART 结果无关。高肾上腺素能和非高肾上腺素能 POTS 患者之间的自主神经测试或频谱指数无差异。
我们的发现证实，很大一部分 POTS 患者存在自主神经出汗功能障碍，其分布通常为斑片状，但与其他自主神经功能测试无关。需要进一步的研究来确定最佳的 POTS 患者内表型方法。
