scholarly journals Neuromodulation With Thoracic Dorsal Root Ganglion Stimulation Reduces Ventricular Arrhythmogenicity

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuki Kuwabara ◽  
Siamak Salavatian ◽  
Kimberly Howard-Quijano ◽  
Tomoki Yamaguchi ◽  
Eevanna Lundquist ◽  
...  
Keyword(s):  
Dorsal Root Ganglion ◽  
High Frequency ◽  
Dorsal Root ◽  
Ventricular Arrhythmias ◽  
Low Frequency ◽  
Electrode Array ◽  
Sympathetic Hyperactivity ◽  
Electrophysiological Recordings ◽  
Before And After ◽  
Yorkshire Pigs

Introduction: Sympathetic hyperactivity is strongly associated with ventricular arrhythmias and sudden cardiac death. Neuromodulation provides therapeutic options for ventricular arrhythmias by modulating cardiospinal reflexes and reducing sympathetic output at the level of the spinal cord. Dorsal root ganglion stimulation (DRGS) is a recent neuromodulatory approach; however, its role in reducing ventricular arrhythmias has not been evaluated. The aim of this study was to determine if DRGS can reduce cardiac sympathoexcitation and the indices for ventricular arrhythmogenicity induced by programmed ventricular extrastimulation. We evaluated the efficacy of thoracic DRGS at both low (20 Hz) and high (1 kHz) stimulation frequencies.Methods: Cardiac sympathoexcitation was induced in Yorkshire pigs (n = 8) with ventricular extrastimulation (S1/S2 pacing), before and after DRGS. A DRG-stimulating catheter was placed at the left T2 spinal level, and animals were randomized to receive low-frequency (20 Hz and 0.4 ms) or high-frequency (1 kHz and 0.03 ms) DRGS for 30 min. High-fidelity cardiac electrophysiological recordings were performed with an epicardial electrode array measuring the indices of ventricular arrhythmogenicity—activation recovery intervals (ARIs), electrical restitution curve (Smax), and Tpeak–Tend interval (Tp-Te interval).Results: Dorsal root ganglion stimulation, at both 20 Hz and 1 kHz, decreased S1/S2 pacing-induced ARI shortening (20 Hz DRGS −21±7 ms, Control −50±9 ms, P = 0.007; 1 kHz DRGS −13 ± 2 ms, Control −46 ± 8 ms, P = 0.001). DRGS also reduced arrhythmogenicity as measured by a decrease in Smax (20 Hz DRGS 0.5 ± 0.07, Control 0.7 ± 0.04, P = 0.006; 1 kHz DRGS 0.5 ± 0.04, Control 0.7 ± 0.03, P = 0.007), and a decrease in Tp-Te interval/QTc (20 Hz DRGS 2.7 ± 0.13, Control 3.3 ± 0.12, P = 0.001; 1 kHz DRGS 2.8 ± 0.08, Control; 3.1 ± 0.03, P = 0.007).Conclusions: In a porcine model, we show that thoracic DRGS decreased cardiac sympathoexcitation and indices associated with ventricular arrhythmogenicity during programmed ventricular extrastimulation. In addition, we demonstrate that both low-frequency and high-frequency DRGS can be effective neuromodulatory approaches for reducing cardiac excitability during sympathetic hyperactivity.

scholarly journals Autonomic Nervous System Function in Infants With Transposition of the Great Arteries

2011 ◽  
Vol 14 (3) ◽  
pp. 257-268 ◽  
Author(s):  
Tondi M. Harrison ◽  
Roger L. Brown
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
High Frequency ◽  
Heart Defects ◽  
Newborn Infants ◽  
Low Frequency ◽  
Autonomic Nervous ◽  
Healthy Infants ◽  
Before And After ◽  
High Risk Infants

The ability to maintain and respond to challenges to homeostasis is primarily a function of the autonomic nervous system (ANS). In infants with complex congenital heart defects this ability may be impaired. This study described change in ANS function before and after surgical correction in infants with transposition of the great arteries (TGA) and in healthy infants. A total of 15 newborn infants with TGA were matched with 16 healthy infants on age, gender, and feeding type. The ANS function was measured using heart rate variability (HRV). Data were collected preoperatively in the 1st week of life and postoperatively before, during, and after feeding at 2 weeks and 2 months of age. Infants with TGA demonstrated significantly lower high-frequency and low-frequency HRV preoperatively ( p < .001) when compared with healthy infants. At 2 weeks, infants with TGA were less likely than healthy infants to demonstrate adaptive changes in high-frequency HRV during feeding (Wald Z = 2.002, p = .045), and at 2 months, 40% of TGA infants exhibited delayed postfeeding recovery. Further research is needed to more thoroughly describe mechanisms of a physiologically adaptive response to feeding and to develop nursing interventions supportive of these high-risk infants.

Usefulness of Thermography in Evaluation of Patients with FBSS Following Radiofrequency Dorsal Root Ganglion Lesioning

2006 ◽  
Vol 321-323 ◽  
pp. 808-812
Author(s):  
Jung Yul Park ◽  
Juno Park ◽  
Sang Dae Kim ◽  
Dong Jun Lim
Keyword(s):  
Dorsal Root Ganglion ◽  
Clinical Improvement ◽  
Dorsal Root ◽  
Clinical Symptoms ◽  
Clinical Status ◽  
Substantial Improvement ◽  
Leg Pain ◽  
Radiographic Findings ◽  
Younger Age ◽  
Before And After

The changes in thermographic pattern were studied, in patients with persistent back and leg pain after surgery, to validate its significance in evaluating the clinical status following percutaneous radiofrequency (PRF) lesioning on dorsal root ganglion. A total of 90 patients with persistent back and leg (52 males, 38 females, mean age 46.2 years) with more than 6 months of duration following lumbar surgeries were enrolled into study. Thermography was performed before and after PRF procedures. PRF procedures were percutaneously done with C-arm guidance and adjustments from physiologic monitoring. Assessments included the clinical symptoms, signs and changes of thermographic pattern before and after PRF procedure. Minimal follow up period was 6 months. All patients tolerated the RF procedures without complications. Thermographic findings before procedures were agreeable to clinical and radiographic findings in 81(90%) of patients. PRF procedure provided substantial improvement of pain (>50% pain reduction) in 69(76.7%) and 63(70%) at 1 and 6 months following procedures. Thermographic findings in 80(88.9%) of these patients seemed to correlate with clinical improvement. However, 12 patients (13.3%) showed no significant thermographic changes despite clinical improvement. Clinical factors that were not statistically significant but were related to better outcome were younger age, unilateral pain, no significant dysesthesia, less number of operations, no instrumentation. Results of this study indicate that thermography may have a specific role in evaluating these patients, especially when comparing with clinical status.

Heart rate variability and dissociation in panic disorder

2011 ◽  
Vol 26 (S2) ◽  
pp. 147-147
Author(s):  
T. Diveky ◽  
D. Kamaradova ◽  
A. Grambal ◽  
K. Latalova ◽  
J. Prasko ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Panic Disorder ◽  
Frequency Band ◽  
High Frequency ◽  
Power Spectra ◽  
Low Frequency ◽  
Very Low Frequency ◽  
Significant Difference ◽  
Before And After

The aim of our study is to measure very low frequency band (VLF), low frequency band (LF) and high frequency band (HF) components of R-R interval during orthostatic experiment in panic disorder patients before and after treatment.MethodsWe assessed heart rate variability in 19 patients with panic disorder before and after 6-weeks treatment with antidepressants combined with CBT and 18 healthy controls. They were regularly assessed on the CGI, BAI and BDI. Heart rate variability was assessed during 5 min standing, 5 min supine and 5 min standing positions before and after the treatment. Power spectra were computed using a fast Fourier transformation for very low frequency - VLF (0.0033 - 0.04 Hz), low-frequency - LF (0.04-0.15 Hz) and high frequency - HF (0.15-0.40 Hz) powers.Results19 panic disorder patients entered a 6-week open-label treatment study with combination of SSRI and cognitive behavioral therapy. A combination of CBT and pharmacotherapy proved to be the effective treatment of patients. They significantly improved in all rating scales. There were highly statistical significant differences between panic patients and control group in all components of power spectral analysis in 2nd and in two component of 3rd (LF and HF in standing) positions. There was also statistically significant difference between these two groups in LF/HF ratio in supine position (2nd). During therapy there was tendency to increasing values in all three positions in components of HRV power spectra, but there was only statistically significant increasing in HF1 component.Supported by project IGA MZ ČR NS 10301-3/2009

scholarly journals Comparison of FDA-Approved Electrical Neuromodulation Techniques for Focal Neuropathic Pain: A Narrative Review of DRG, HF10, and Burst Neuromodulation

2021 ◽  
pp. E407-E423
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Dorsal Root Ganglion ◽  
Spinal Cord Stimulation ◽  
High Frequency ◽  
Dorsal Root ◽  
Case Reports ◽  
Case Series ◽  
Dorsal Column ◽  
Small Sample

BACKGROUND: Evidence suggests that dorsal root ganglion stimulation (DRGS) is a more effective treatment for focal neuropathic pain (FNP) compared with tonic, paresthesia-based dorsal column spinal cord stimulation (SCS). However, new advancements in waveforms for dorsal column SCS have not been thoroughly studied or compared with DRGS for the treatment of FNP. OBJECTIVES: The purpose of this review was to examine the evidence for these novel technologies; to highlight the lack of high-quality evidence for the use of neuromodulation to treat FNP syndromes other than complex regional pain syndrome I or II of the lower extremity; to emphasize the absence of comparison studies between DRGS, burst SCS, and high-frequency SCS; and to underscore that consideration of all neuromodulation systems is more patient-centric than a one-size-fits-all approach. STUDY DESIGN: This is a review article summarizing case reports, case series, retrospective studies, prospective studies, and review articles. SETTING: The University of Miami, Florida. METHODS: A literature search was conducted from February to March 2020 using the PubMed and EMBASE databases and keywords related to DRGS, burst SCS, HF10 (high-frequency of 10 kHz), and FNP syndromes. All English-based literature from 2010 reporting clinical data in human patients were included. RESULTS: Data for the treatment of FNP using burst SCS and HF10 SCS are limited (n = 11 for burst SCS and n = 11 for HF10 SCS). The majority of these studies were small, single-center, nonrandomized, noncontrolled, retrospective case series and case reports with short follow-up duration. To date, there are only 2 randomized controlled trials for burst and HF10 for the treatment of FNP. LIMITATIONS: No studies were available comparing DRGS to HF10 or burst for the treatment of FNP. Data for the treatment of FNP using HF10 and burst stimulation were limited to a small sample size reported in mostly case reports and case series. CONCLUSIONS: FNP is a complex disease, and familiarity with all available systems allows the greatest chance of success. KEY WORDS: Dorsal root ganglion, high frequency, burst, spinal cord stimulation, neuromodulation, focal neuropathic pain

scholarly journals Impact of TBI, PTSD, and Hearing Loss on Tinnitus Progression in a US Marine Cohort

2019 ◽  
Vol 184 (11-12) ◽  
pp. 839-846 ◽  
Author(s):  
Royce E Clifford ◽  
Dewleen Baker ◽  
Victoria B Risbrough ◽  
Mingxiong Huang ◽  
Kate A Yurgil
Keyword(s):  
Hearing Loss ◽  
Traumatic Stress ◽  
High Frequency ◽  
Low Frequency ◽  
Treatment Programs ◽  
Post Traumatic Stress ◽  
Increased Risk ◽  
Before And After ◽  
Post Traumatic ◽  
New Onset

Abstract Introduction Mild TBI (TBI) is associated with up to a 75.7% incidence of tinnitus, and 33.0% of tinnitus patients at the US Veterans Administration carry a diagnosis of post-traumatic stress syndrome (PTSD). Yet factors contributing to new onset or exacerbation of tinnitus remain unclear. Materials and Methods Here we measure intermittent and constant tinnitus at two time points to ascertain whether pre-existing or co-occurring traumatic brain injury (TBI), hearing loss, or post-traumatic stress disorder (PTSD) predicts new onset, lack of recovery and/or worsening of tinnitus in 2,600 United States Marines who were assessed before and after a combat deployment. Results Ordinal regression revealed that constant tinnitus before deployment was likely to continue after deployment (odds ratio [OR] = 28.62, 95% confidence interval [CI]: 9.84,83.26). Prior intermittent tinnitus increased risk of post-deployment constant tinnitus (OR = 4.95, CI: 2.97,8.27). Likelihood of tinnitus progression increased with partial PTSD (OR = 2.39, CI: 1.50,3.80) and TBI (OR = 1.59, CI: 1.13,2.23), particularly for blast TBI (OR = 2.01, CI: 1.27,3.12) and moderate to severe TBI (OR = 2.57, CI: 1.46,4.51). Tinnitus progression also increased with low frequency hearing loss (OR = 1.94, CI: 1.05,3.59), high frequency loss (OR = 3.01, CI: 1.91,4.76) and loss across both low and high frequency ranges (OR = 5.73, CI: 2.67,12.30). Conclusions Screening for pre-existing or individual symptoms of PTSD, TBI, and hearing loss may allow for more focused treatment programs of comorbid disorders. Identification of those personnel vulnerable to tinnitus or its progression may direct increased acoustic protection for those at risk.

scholarly journals Influence of Autonomic Control on the Specific Intermittent Performance of Judo Athletes

2018 ◽  
Vol 64 (1) ◽  
pp. 99-109
Author(s):  
Bruno T. Campos ◽  
Eduardo M. Penna ◽  
João G.S. Rodrigues ◽  
Mateus Diniz ◽  
Thiago T. Mendes ◽  
...  
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Training Experience ◽  
Specific Performance ◽  
Before And After ◽  
Post Test ◽  
Judo Athletes ◽  
The Mean ◽  
Hrv Analysis ◽  
Different Levels

Abstract Judo is a high-intensity intermittent combat sport which causes cardiac adaptations both morphologically and related to the autonomic nervous system (ANS). Therefore, this study aims to verify the correlation between heart rate variability (HRV) at rest with performance in the Special Judo Fitness Test (SJFT) and whether groups with different RR values at rest show different performance in the SJFT and during post-test recovery. Sixteen judo athletes with 7.2 ± 3.9 years of training experience participated in the study. Before and after the SJFT execution HRV and lactate measurements were conducted. For HRV analysis, we used the mean interval RR, the standard deviation of the RR interval (SDNN), the root mean square of successive differences in RR intervals (RMSSD), the low frequency (LF) and high frequency (HF) in normalized and absolute units. The sample was split into two groups (low RR and high RR) to verify if this variable could differentiate between specific performance. For the SDNN, a significant and moderate correlation (r = 0.53) was found with the total number of throws and throws in the series A (r = 0.56) and B (r = 0.54) and for the RMSSD a correlation with throws during series B (r = 0.59) in the SJFT. However, the groups did not differ in performance and recovery. Therefore, HRV is related to intermittent judo performance; however, it cannot differentiate between judokas at different levels of performance.

Effects of low frequency vibration on the dorsal root ganglion

Pain ◽  
1987 ◽  
Vol 30 ◽  
pp. S92
Author(s):  
J. Weinstein ◽  
M. Pope ◽  
R. Schmidt ◽  
R. Seroussi
Keyword(s):  
Dorsal Root Ganglion ◽  
Dorsal Root ◽  
Low Frequency ◽  
Low Frequency Vibration

Maximal results with minimal stimuli: the fewest high-frequency pulses needed to measure or model prolonged low-frequency force depression in the dorsiflexors

2021 ◽  
Author(s):  
Luca Ruggiero ◽  
Christina D. Bruce ◽  
Hannah B. Streight ◽  
Chris J. McNeil
Keyword(s):  
Gold Standard ◽  
High Frequency ◽  
Low Frequency ◽  
Pulse Number ◽  
Limits Of Agreement ◽  
Force Depression ◽  
Before And After ◽  
Minimum Number ◽  
Experimental Values ◽  
Further Development

Quantifying prolonged low-frequency force depression (PLFFD) with the gold-standard 1-s trains presents challenges so paired-pulses have been used. Owing to greater impairment of high-frequency doublet than tetanic torque, paired-pulses underestimate PLFFD. This study aimed to approximate the minimum number of high-frequency pulses needed to avoid such underestimation and assess the feasibility of modelling PLFFD from a limited number of experimental pulses. In 13 participants, a 1-s 10-Hz train and 100-Hz trains with 2, 4, 7, 12, 15, 25, 50, or 100 pulses were evoked before and after (15 min, 2, 4, and 7 d) eccentric exercise of the dorsiflexors. With ≤ 12 pulses, impairment of 100-Hz torque was greater than the 1-s train (P ≤ 0.05; e.g., 12 vs. 100 pulses at 4d: 97.8 ± 8.5% vs. 100.5 ± 8.2% baseline). Consequently, with ≤ 12 pulses, PLFFD was underestimated compared to the gold-standard measure (P ≤ 0.05; e.g., 12 vs. 100 pulse 10:100 Hz torque ratio at 4d: 86.8 ± 12.8% vs. 84.6 ± 13.5% baseline). Modelling reproduced 10:100 Hz ratios (PLFFD) with 95% limits of agreement of −13.6-16.7% of experimental values with ≥ 12 pulses. Our results indicate that a minimum of 13-25 100-Hz pulses are needed to accurately quantify PLFFD in the dorsiflexors. Although this may not be the minimum range for other muscles, a similar relationship with pulse number likely exists. Modelling may eventually provide an option to estimate PLFFD from experimental trains with relatively few pulses; however, further development is imperative to reduce variability.

Effect of hot arm and foot bath on heart rate variability and blood pressure in healthy volunteers

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Samruddhi Chintaman Vyas ◽  
A. Mooventhan ◽  
N. K. Manjunath
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Healthy Volunteers ◽  
High Frequency ◽  
Low Frequency ◽  
Healthy Male ◽  
Before And After ◽  
Instantaneous Heart Rate ◽  
The Mean

AbstractBackgroundThough hot arm and foot bath (HAFB) is widely used, a precise physiological response is not reported. Hence, the present study was conducted to evaluate the effect of HAFB on heart rate variability (HRV) and blood pressure (BP) in healthy volunteers.Materials and MethodsSixteen healthy male volunteers’ aged 23.81 ± 5.27 (mean ± standard deviation) years were recruited. All the subjects underwent only one session of HAFB (104-degree Fahrenheit) for the duration of 20 min. Assessments such as Electrocardiography and BP were taken before and after the intervention.ResultsResults of this study showed a significant reduction in systolic-BP (SBP), diastolic-BP (DBP), mean arterial pressure (MAP), the mean of the intervals between adjacent QRS complexes or the instantaneous heart rate (RR interval), the number of interval differences of successive NN intervals greater than 50 ms (NN50), the proportion derived by dividing NN50 by the total number of NN intervals (pNN50), and high frequency (HF) band of HRV along with a significant increase in heart rate (HR), low-frequency (LF) band of HRV and LF/HF ratio compared to its baseline.ConclusionsResults of this study suggest that 20 min of HAFB produce a significant increase in HR and a significant reduction in SBP, DBP, and MAP while producing parasympathetic withdrawal.

scholarly journals A “Goldilocks” Approach to Hearing-Aid Self-Fitting: User Interactions

2017 ◽  
Vol 26 (3S) ◽  
pp. 430-435 ◽  
Author(s):  
Arthur Boothroyd ◽  
Carol Mackersie
Keyword(s):  
Speech Perception ◽  
High Frequency ◽  
Hearing Aid ◽  
Low Frequency ◽  
User Interactions ◽  
Before And After ◽  
Fitting Procedures ◽  
Feasible Alternative ◽  
Highly Correlated ◽  
Selection Of

Purpose The purpose of the current study was to evaluate user reactions to custom software designed for self-adjustment of amplification. Method “Goldilocks” software was developed to allow user exploration and selection of preferred levels of overall output, low-frequency cut, and high-frequency boost while listening to preprocessed speech. Thirteen hearing-aid users and 13 nonusers self-adjusted before and after taking a speech perception test incorporated into the software. Results All 26 participants were able to complete the 2 adjustments and the intervening test in an average of 6.5 min—20 of them from on-screen instructions without experimenter help. Relative to a generic starting condition, the average participant opted to increase overall output, reduce low-frequency cut, and increase high-frequency boost. The first and second self-selected values were highly correlated, but there was evidence of further increases of overall volume and high-frequency boost after speech perception testing with the initial adjustment. There was no evidence that prior hearing-aid experience affected the ability to understand or complete the self-fitting process. Conclusions This approach to hearing-aid self-fitting can be a speedy, reliable, and feasible alternative to, or supplement to, conventional fitting procedures, but many questions remain to be answered.

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