Orthostatic Intolerance and Gastrointestinal Motility in Adolescents With Nausea and Abdominal Pain

To describe the relationships between gastric emptying, autonomic function, and postural tachycardia in adolescent patients with nausea and/or abdominal discomfort. It was hypothesized that patients with both gastrointestinal symptoms and symptoms of orthostatic intolerance are more likely to show abnormal tilt table results and delayed gastric emptying. A retrospective review was conducted of adolescent patients who came to a pediatric referral center because of nausea and dyspepsia and who subsequently underwent both autonomic reflex screening and gastric emptying testing. Patients with a heart rate change of 30 or more beats per minute on the heads-up tilt table test were assigned to the postural orthostatic tachycardia syndrome (POTS) group (n = 21), and those with a heart rate change of fewer than 30 beats per minute on the heads-up tilt table test were assigned to the non-POTS group (n = 10). There was no significant difference between the POTS and non-POTS groups with regard to presenting symptoms (P > 0.05). Overall, 13 (42%) individuals had abnormal gastric emptying results (delayed in 6, accelerated in 7), but gastric emptying scores were similar between the POTS and non-POTS groups. Furthermore, there was no correlation between an individual's gastric emptying results at 1, 2, and 4 hours and that person's heart rate change on HUT (r = −0.05, −0.15, and −0.19). Although altered gastric emptying and postural tachycardia are common in a referral population of adolescents with nausea and/or abdominal discomfort, the clinical presentation was not predictive of test results. Furthermore, delayed gastric emptying was not correlated with the current definition of postural tachycardia.