Abstract Details

Title The Pathophysiology of Neuropathic and Non-Neuropathic Postural Tachycardia Syndrome

Topic Autonomic Disorders

Presentation(s) P03 - (-)

Poster/Presentation
Number 036

Objective

Background BACKGROUND: The postural tachycardia syndrome (POTS) is defined as an exaggerated heart rate in the upright position with symptoms of orthostatic intolerance. Some patients with POTS have an underlying small fiber neuropathy.

Design/Methods DESIGN/METHODS: Twenty-four subjects with POTS and 10 healthy controls 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 categorized as neuropathic and non-neuropathic POTS, based on abnormal IENFD and/or heat and heat-pain detection thresholds. Differences in autonomic function and symptom questionnaires were analyzed by ANOVA with corrections for multiple analyses. Significance was set at P<0.05.

Results RESULTS: POTS subjects had greater fatigue, anxiety, physical impairment, orthostatic intolerance and perceived disability than controls (P<0.0001 all questionnaires). Individuals with non-neuropathic POTS had greater anxiety, orthostatic intolerance and perceived disability than those with neuropathic POTS. Neuropathic POTS subjects had higher resting heart rates (67±5 POTS vs. 77±4 beats/min controls P<0.05) but lower upright heart rates (P<0.05), lower heart rate variability (28.3±7.4 POTS vs. 19.8±5.4 beats/min controls; P<0.05) and lower Valsalva ratios (P<0.05). POTS subjects had lower IENFD at the distal leg than controls (P<0.05). Non-neuropathic POTS subjects had nerve densities similar to controls.

Conclusions CONCLUSIONS: Small fiber sensory neuropathy measures may be used to differentiate POTS subtypes. Individuals with non-neuropathic POTS have greater anxiety, orthostatic intolerance and perceived disability despite better overall autonomic function than those with neuropathic POTS. These findings suggest that different pathophysiological mechanisms that underlie the postural tachycardia in neuropathic and non-neuropathic POTS. These findings may have implications for therapeutic interventions to treat this disorder.

Authors/Disclosures
Christopher H. Gibbons, MD, FAAN (Beth Israel Deaconess Medical Center) PRESENTER	Dr. Gibbons has received personal compensation for serving as an employee of CND Life Sciences. Dr. Gibbons has or had stock in CND Life Sciences.Dr. Gibbons has received publishing royalties from a publication relating to health care.
	No disclosure on file
	No disclosure on file
Roy L. Freeman, MD (Beth Israel Deaconess Hosp)	Dr. Freeman has received personal compensation in the range of $50,000-$99,999 for serving as a Consultant for Cutaneous Diagnostic Life Sciences. Dr. Freeman has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Vertex. Dr. Freeman has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Theravance. Dr. Freeman has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for Inhibikase. Dr. Freeman has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier. The institution of Dr. Freeman has received research support from NIH. The institution of Dr. Freeman has received research support from Theravance. The institution of Dr. Freeman has received research support from Biohaven. The institution of Dr. Freeman has received research support from Lundbeck. Dr. Freeman has received research support from Regeneron.
Edward Fox, MD, PhD, FAAN	Dr. Fox has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Alexion Pharmaceuticals. Dr. Fox has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Genentech. Dr. Fox has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Biogen. Dr. Fox has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for EMD Serono. Dr. Fox has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for GW Pharmaceuticals. Dr. Fox has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for TG Therapeutics. Dr. Fox has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Bristol Myers Squibb. Dr. Fox has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Dr. Fox has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Dr. Fox has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Alexion. Dr. Fox has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Biogen. Dr. Fox has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Genentech. Dr. Fox has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Bristol Myers Squibb. The institution of Dr. Fox has received research support from Biogen. The institution of Dr. Fox has received research support from Genentech. The institution of Dr. Fox has received research support from Celgene - BMS. The institution of Dr. Fox has received research support from Chugai. The institution of Dr. Fox has received research support from Novartis. The institution of Dr. Fox has received research support from EMD-Serono. The institution of Dr. Fox has received research support from TG Therapeutics. The institution of Dr. Fox has received research support from AbbVie. The institution of Dr. Fox has received research support from Sanofi Genzyme. The institution of Dr. Fox has received research support from AbbVie.

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