Abstract 15291: ‘Heart Rate Deficit’ From Dysautonomia in a Bariatric Surgery Patient - An Unusual Cause of Recurrent Syncope

Background: Patients undergoing bariatric surgery are prone to develop symptomatic dysautonomia but the mechanisms remain unclear. Methods: N/A Results: A 61-year-old female with hyperlipidemia, fibromyalgia, morbid obesity status post gastric sleeve 2 years prior, was transferred to our institution after an unremarkable initial cardiac workup for recurrent syncope and bradycardia. Patient had significant weight loss (180 lbs) post-surgery over this 2-year period but began noticing increasing fatigue, and exercise intolerance in the last four months preceding recent syncopal episodes. Syncopal spells happened while trying to lift her head >60 degrees/sit up from a recumbent position. Baseline heart rate (HR) was 36-42 bpm (Figure lower Panel) while it was 75-90 bpm immediately following bariatric surgery (Figure upper panel). Blood pressure was normal. During witnessed syncopal episodes, HR remained in the 35-40 bpm range with no asystolic pauses and normal blood pressure. Video EEG showed loss of brain electrical activity during syncope; no seizure activity was noted. Progressive decline in HR and baseline bradycardia was suspected as the cause and she underwent permanent pacemaker implantation, which resulted in complete resolution of symptoms and no recurrence of syncope at 6-mo follow-up. Conclusion: We describe a unique case where marked decline in resting HR occurred in association with significant weight loss following bariatric surgery. This ‘HR deficit’ and resting bradycardia, likely due to dysautonomia, resulted in recurrent syncope without asystole or vasodepression, and completely resolved with permanent pacemaker implantation.