Cardiac and Respiratory Changes in Epileptic Baboons with “microburst” VNS Therapy
Abstract number :
2.065
Submission category :
1. Translational Research: 1D. Devices, Technologies, Stem Cells
Year :
2017
Submission ID :
350042
Source :
www.aesnet.org
Presentation date :
12/3/2017 3:07:12 PM
Published date :
Nov 20, 2017, 11:02 AM
Authors :
Melissa De La Garza, Texas Biomedical Research Institute; David Poldiak, EMKA Technologies, Inc., Falls Church, Virginia; Robert Shade, Texas Biomedical Research Institute; Alexander M. Papanastassiou, UT Health San Antonio; and Charles A. Szabo, UT Healt
Rationale: High-frequency “microburst” vagal nerve stimulation (VNS) may result in improved efficacy over standard low-frequency therapy. As a natural model for genetic generalized epilepsy, the epileptic baboon offers an ideal platform for evaluating the effect of microburst VNS therapy on autonomic markers, including heart (HR) and respiratory (RR) rates, and heart rate variability (HRV). Methods: Two epileptic female baboons (EB1 16 and EB2 10 years old), were evaluated before microburst therapy, and compared to untreated healthy, asymptomatic female (4 year old). The baboons were monitored using emkaPACK4G wireless system for a mean 22 hours (Table 1). Four electrodes were used to generate ECG, one resistance impedance plethysmography band was placed over the lower thorax, and one temperature sensor was placed midsternally, and maintained using a custom-fit vest. Recordings were repeated in the epileptic baboons after 4 to 6 weeks of continuous microburst VNS therapy to evaluate treatment effects. HR and RR were assessed over the entire study, but also for afternoon (awake), overnight (sleep) and morning (awake) samples, corroborated by video and accelerometry. Intervals between adjacent QRS complexes (NN-intervals) were used to calculate heart variability (standard deviation of NN intervals, square root of the mean of the sum of squares of their differences). Results: Baseline HR and HRV were decreased in EB2 compared to CB and EB1 (Table). There was a statistically insignificant trend for HR decreases after VNS therapy, but no change in HRV, in both epileptic baboons. Baseline RR appears marginally higher in epileptic baboons compared to CB, with additional statistically insignificant increases with VNS therapy. Conclusions: This pilot study confirms previously reported stability of HR and HRV in healthy Beagles exposed to “microburst” VNS treatment. Microburst VNS therapy may reduce HR in epileptic baboons, but does not appear to affect respiratory rhythms, or alter the diurnal pattern of HR or RR. Funding: Livanova, Inc., 159292
Translational Research