The value of autonomic testing in postural tachycardia syndrome
ABSTRACT Postural tachycardia syndrome (POTS) is a fairly common condition that may or may not be associated with autonomic neuropathy. In a retrospective analysis, we compared two groups of patients based on clinical and autonomic criteria, those with POTS in isolation (POTS-Alone), and POTS with evidence of autonomic neuropathy (POTS-AN). Of 260 records reviewed, 57 patients met the criteria for POTS; 38 (67%) patients assigned to the POTS-Alone group and 19 (33%) patients assigned to the POTS-AN group. A decreased sweat output on the quantitative sudomotor axon reflex test is the most frequent abnormal finding in the POST-AN group suggesting sympathetic cholinergic neuropathy. Clinically, headache and gastrointestinal symptoms were more frequent among the POTS-AN group. Therefore, POTS may exist in isolation and may differ from those associated with AN.
SourceAvailable from: Pedro Jimenez - CohlRevista medica de Chile 02/2012; 140(2):145-152. DOI:10.4067/S0034-98872012000200001 · 0.37 Impact Factor
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ABSTRACT: To define the neuropathology, clinical phenotype, autonomic physiology and differentiating features in individuals with neuropathic and non-neuropathic postural tachycardia syndrome (POTS). Twenty-four subjects with POTS and 10 healthy control subjects had skin biopsy analysis of intra-epidermal nerve fiber density (IENFD), quantitative sensory testing (QST) and autonomic testing. Subjects completed quality of life, fatigue and disability questionnaires. Subjects were divided into neuropathic and non-neuropathic POTS, defined by abnormal IENFD and abnormal small fiber and sudomotor function. Nine of 24 subjects had neuropathic POTS and had significantly lower resting and tilted heart rates; reduced parasympathetic function; and lower phase 4 valsalva maneuver overshoot compared with those with non-neuropathic POTS (P<0.05). Neuropathic POTS subjects also had less anxiety and depression and greater overall self-perceived health-related quality of life scores than non-neuropathic POTS subjects. A sub-group of POTS patients (cholinergic POTS) had abnormal proximal sudomotor function and symptoms that suggest gastrointestinal and genitourinary parasympathetic nervous system dysfunction. POTS subtypes may be distinguished using small fiber and autonomic structural and functional criteria. Patients with non-neuropathic POTS have greater anxiety, greater depression and lower health-related quality of life scores compared to those with neuropathic POTS. These findings suggest different pathophysiological processes underlie the postural tachycardia in neuropathic and non-neuropathic POTS patients. The findings have implications for the therapeutic interventions to treat this disorder.PLoS ONE 12/2013; 8(12):e84716. DOI:10.1371/journal.pone.0084716 · 3.53 Impact Factor