481 Motility Abnormalities Identified by Wireless Motility Capsule in Postural Orthostatic Tachycardia Syndrome

Abstract

INTRODUCTION: Gastrointestinal symptoms are common in patients with postural tachycardia syndrome (POTS). Previous studies have reported a wide range of abnormalities, particularly delayed gastric emptying in POTS. Wireless motility capsule (WMC) is a minimally invasive test that allows the evaluation of gastrointestinal physiology. We aimed to investigate the diagnostic yield of WMC in patients with POTS. METHODS: We conducted a retrospective review of all patients at our institution with both formal WMC testing (SmartpillTM) and autonomic testing for evaluation of gastrointestinal and neurological symptoms respectively. Patient demographics and results of respective testing were extracted. We compared transit abnormalities and contraction patterns between patients meeting diagnostic criteria for POTS and those without POTS. Transit abnormality percentages were compared using chi2 testing, and contraction pattern parameters were compared using 2-sample t-testing. RESULTS: A total of 27 women with both WMC and autonomic testing were studied. The mean age was 39.6 (range 18-68). Fourteen patients had POTS, while the other 13 had either mild or no autonomic abnormalities. Patients with POTS were more likely to have delayed small bowel transit (42.9% vs 7.69%, P = 0.037), but no differences were seen in gastric or colonic transit delays (Table 1). Additionally, POTS patients were more likely to exhibit a hypocontractile pattern throughout the gastrointestinal tract compared to non-POTS patients. Specifically, maximal gastric pressure, and small bowel peak amplitude and motility index were significantly lower in POTS patients. There was a trend towards lower colonic maximum pressure, contraction/min and peak amplitude in POTS patients that did not reach significance (Table 1). CONCLUSION: Our data shows that gastrointestinal motility abnormalities, as observed in WMC, are more common in patients with POTS. Patients with POTS were more likely to have delayed small bowel transit, as well as hypocontractile gastrointestinal patterns, particularly in the small bowel, compared to non-POTS patients. WMC offers a unique opportunity to evaluate patients with autonomic dysfunction and POTS. Further prospective evaluation and higher sample sizes are needed.