Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Clin Auton Res. 2013 Aug;23(4):181-8. doi: 10.1007/s10286-013-0199-5. Epub 2013 Jun 1.
Chronic symptoms of orthostatic intolerance occur in postural tachycardia syndrome (POTS) and patients with orthostatic intolerance (OI) without tachycardia. We recently reported that deconditioning is almost universal in both patient groups. In this study, we focussed on the question of how much dysautonomia, besides orthostatic tachycardia, is there in POTS vs. OI, and how the two groups compare in regards to clinical, autonomic, laboratory, and exercise variables.
We retrospectively studied all patients referred for orthostatic intolerance at Mayo Clinic between January 2006 and June 2011, who underwent standardized autonomic and exercise testing.
Eighty-four POTS and 100 OI fulfilled inclusion criteria, 89 % were females. The mean age was 25 and 32 years, respectively. Clinical presentation, autonomic parameters, laboratory findings, and degree of deconditioning were overall similar between the two groups, except for the excessive orthostatic heart rate (HR) rise and mild vasomotor findings observed in POTS but not in OI (slightly larger Valsalva ratio and incomplete blood pressure recovery during Valsalva). Both groups responded poorly to various medications. Severely deconditioned patients were similar to non-deconditioned patients, except for 24 h urine volume (1,555 vs. 2,417 ml), sweat loss on thermoregulatory sweat test (1.5 vs. 0.5 %), and few respiratory parameters during exercise, which are likely clinically insignificant.
Though similar in clinical presentation, POTS and OI are different entities with greater, albeit still mild, dysautonomia in POTS. The clinical and pathophysiological relevance of minimal dysautonomia in the absence of orthostatic tachycardia as seen in OI remain uncertain.
直立不耐受的慢性症状发生在体位性心动过速综合征（POTS）和直立不耐受（OI）患者中，这些患者没有心动过速。我们最近报道称，去适应在这两个患者群体中几乎都是普遍存在的。在这项研究中，我们专注于以下问题：除了直立性心动过速外，POTS 与 OI 之间存在多少自主神经功能障碍，以及这两个群体在临床、自主神经、实验室和运动变量方面的比较如何。
我们回顾性研究了 2006 年 1 月至 2011 年 6 月期间在梅奥诊所因直立不耐受而转诊的所有患者，这些患者接受了标准化的自主神经和运动测试。
84 名 POTS 和 100 名 OI 符合纳入标准，89%为女性。平均年龄分别为 25 岁和 32 岁。两组之间的临床表现、自主神经参数、实验室发现和去适应程度总体相似，但 POTS 组存在过度的直立性心率（HR）升高和轻度血管运动异常，而 OI 组则没有（稍大的瓦尔萨尔瓦比值和瓦尔萨尔瓦期间血压恢复不完全）。两组对各种药物的反应都很差。严重去适应的患者与非去适应的患者相似，除了 24 小时尿量（1555 与 2417ml）、体温调节出汗试验中出汗量（1.5 与 0.5%）以及运动期间的一些呼吸参数，这些参数可能临床上无意义。
尽管临床表现相似，但 POTS 和 OI 是不同的实体，POTS 中存在更大的自主神经功能障碍，尽管仍然较轻。OI 中所见的无直立性心动过速的最小自主神经功能障碍的临床和病理生理相关性仍然不确定。
