Tilting Cerebral Blood Flow and Standing Balance in Postural Orthostatic Tachycardia Syndrome

Abstract

Introduction: The prevalence and costs of the obesity epidemic and obesity-related conditions including diabetes mellitus is relentlessly increasing worldwide. Bariatric medicine is attempting to address this with weight loss and exercise programmes, and with increasing frequency, various forms of bariatric surgery. There has been considerable success reported after bariatric surgery but not without complications (1, 2, 3). Methods: We describe 13 patients referred in the last 5 years with orthostatic intolerance, who had undergone bariatric surgery. We report on orthostatic intolerance and the results of cardiovascular autonomic testing and the associated and/or causative findings. Results: Autonomic testing using established protocols (4) revealed 4 patients exhibiting PoTS, 6 patients with pre-syncope/syncope and 9 patients with low resting blood pressure. Conclusions: We have reviewed the literature and speculate on the possible mechanisms. We propose that the incidence of orthostatic intolerance due to autonomic dysfunction is higher than considered, that certain cohorts may be more susceptible to complications, and that further research is needed to identify the prevalence, and ideally anticipate occurrence. Further understanding of the pathophysiological processes causing autonomic dysfunction with different bariatric interventions will aid management, which may differ in those with an underlying disposition to autonomic involvement, such as diabetics in whom such procedures are increasingly used.