Improved Heart Rate Variability Research Articles

Improvement in Heart Rate Variability Without Treatment: A Case Study

Improvement in Heart Rate Variability Without Treatment: A Case Study

Enhancing emotion regulation: investigating the efficacy of transcutaneous electrical acupoint stimulation at PC6 in reducing fear of heights.

This study investigated the impact of transcutaneous electrical acupoint stimulation (TEAS) at Neiguan acupoint (PC6) on the physiological and behavioral responses of participants exposed in virtual height. 40 participants were included in the study and were randomly assigned to either a control group or an intervention group. Participants had an immersive experience with a VR interactive platform that provided somatosensory interaction in height stimulation scenes. Psychological scores, behavioral and cognitive performance, and physiological responses were recorded and analyzed. The results indicated that the intervention group had significantly lower fear scores compared to the control group. Analysis of heart rate variability revealed that the intervention group exhibited improved heart rate variability, indicating enhanced cardiovascular function and emotion regulation. The behavioral and cognitive results demonstrated that the intervention group exhibited higher left eye openness, faster reaction times, and greater movement distance, suggesting enhanced attentional focus, cognitive processing, and reduced avoidance behaviors. These findings suggest that TEAS at PC6 can effectively reduce fear and improve the regulation of physiological and behavioral responses to negative emotional stimuli.

Chronic Expression of Interleukin-10 Transgene Modulates Cardiac Sympathetic Ganglion Resulting in Reduced Ventricular Arrhythmia.

The cardiac autonomic nervous system (CANS) is intimately connected to the regulation of electrophysiology and arrhythmogenesis in cardiac systems. This work aimed at investigating whether interleukin-10 (IL-10) could effectively modulate CANS and suppress ischemia-induced ventricular arrhythmia (VA) through chronically acting on the cardiac sympathetic ganglion (CSG). Using an adeno-associated virus (AAV), we achieved local chronic overproduction of IL-10 in the CSG, left stellate ganglion (LSG). As a result, in the IL-10 group, we observed a decreased number of tyrosine hydroxylase-positive (TH+) cells in the LSG. IL-10 markedly downregulated the nerve growth factor, synaptophysin, as well as growth-associated protein 43 expression. In vivo, results from ambulatory electrocardiography showed that IL-10 overexpression significantly inhibited the cardiac sympathetic nervous system activity and improved heart rate variability. Meanwhile, we observed decreased LSG function as well as prolonged ventricular effective refractory period and suppressed VA after myocardial infarction (MI) in the IL-10 group. In addition, IL-10 overexpression attenuated inflammation and decreased norepinephrine levels in the myocardium after acute MI. In conclusion, our data suggest that chronic IL-10 overexpression modulates cardiac sympathetic nerve remodeling and suppresses VA induced by MI. Neuromodulation through AAV-mediated IL-10 overexpression may have the characteristics of and advantages as a potential neuroimmunotherapy for preventing MI-induced VAs.

Far-infrared stimulation of Neiguan acupoints improves heart rate variability and ameliorate fatigue in hemodialysis patients: A randomized trial.

In 2018, 84 615 patients in Taiwan received hemodialysis, of which about 62% to 97% suffered from fatigue. Fatigue caused by hemodialysis may be mental or physical. However, the detailed mechanism remains unclear. This study aimed to evaluate whether far-infrared stimulation of the Neiguan acupoint (P6) could effectively reduce fatigue and improve heart rate variability (HRV) in hemodialysis patients. We conducted a two-arm, randomized trial in a hemodialysis center between March 2015 and March 2016. A total of 73 hemodialysis patients were included and were randomly assigned to an experimental group (n = 37) and a control group (n = 36). The experimental group received far-infrared radiation on Neiguan acupoint during hemodialysis for 12 weeks. The outcomes were fatigue level and HRV. All patients showed moderate fatigue ( M = 26.00 ± 13.01, range = 0-78) at baseline. Far-infrared stimulation on Neiguan acupoint significantly reduced overall fatigue ( β = 24, p < 0.001) and improved HRV ( β = 74.36, p < 0.001). Compared to the control group, the experiment group had significantly reduced fatigue levels in all aspects such as reduced energy and motivation ( β = -2.97, p < 0.001), reduced physical strength ( β = -1.28, p < 0.01), reduced mental capability ( β = -2.38, p < 0.001), reduction in daily activities ( β = -1.48, p < 0.01), depressed mood and loss of control ( β = -1.21, p < 0.05) as well as increased autonomous nervous system activity ( β = 14.71, p < 0.01) in the third month of stimulation. Far-infrared stimulation of the Neiguan acupoints effectively reduces fatigue and increases autonomic nervous system activity in hemodialysis patients.

Comparing the Effectiveness of a Mindfulness-Based Intervention and Progressive Muscle Relaxation in a Military Context

ObjectivesWhile stressors of military deployment are known to have profound effects on health, less is known about effective methods for promoting health. A few studies have examined the effectiveness of mindfulness-based interventions (MBIs) in this context; however, fewer have used an active control group and objective health indicators. Therefore, this study examined the effects of an MBI in comparison to a similarly structured traditional stress management intervention (progressive muscle relaxation, PMR) on health indicators among military personnel.MethodUsing a 2 (pre vs. post) × 3 (group: MBI, PMR vs. inactive control group, ICG) experimental mixed design, participants (MBI, n = 118; PMR, n = 55; ICG, n = 156) answered baseline and post-intervention self-reported measures. Physiological parameters were assessed before and after each session.ResultsResults showed that MBI is superior to PMR and ICG, leading to higher increases in mindfulness, positive affect, and self-care, and greater decreases in physical complaints. This is also confirmed by objective data. Participants in the MBI demonstrated improved heart rate variability and reduced heart rate, while no change was evident for PMR and ICG. However, both MBI and PMR were equally effective in reducing strain.ConclusionsThis study provides further evidence for the effectiveness of MBIs in this specific professional group based on rigorous methodology (comparing to a competing intervention, self-reported and objective measures). MBI is even more effective than PMR as a traditional health intervention in terms of promoting mindfulness, positive affect, and health behavior, as well as reducing complaints.PreregistrationThis study is not preregistered.

Ryanodine receptor 2 inhibition reduces dispersion of cardiac repolarization, improves contractile function, and prevents sudden arrhythmic death in failing hearts

Sudden cardiac death (SCD) from ventricular tachycardia/fibrillation (VT/VF) is a leading cause of death, but current therapies are limited. Despite extensive research on drugs targeting sarcolemmal ion channels, none have proven sufficiently effective for preventing SCD. Sarcoplasmic ryanodine receptor 2 (RyR2) Ca2+ release channels, the downstream effectors of sarcolemmal ion channels, are underexplored in this context. Recent evidence implicates reactive oxygen species (ROS)-mediated oxidation and hyperactivity of RyR2s in the pathophysiology of SCD. We tested the hypothesis that RyR2 inhibition of failing arrhythmogenic hearts reduces sarcoplasmic Ca2+ leak and repolarization lability, mitigates VT/VF/SCD and improves contractile function. We used a guinea pig model that replicates key clinical aspects of human nonischemic HF, such as a prolonged QT interval, a high prevalence of spontaneous arrhythmic SCD, and profound Ca2+ leak via a hyperactive RyR2. HF animals were randomized to receive dantrolene (DS) or placebo in early or chronic HF. We assessed the incidence of VT/VF and SCD (primary outcome), ECG heart rate and QT variability, echocardiographic left ventricular (LV) structure and function, immunohistochemical LV fibrosis, and sarcoplasmic RyR2 oxidation. DS treatment prevented VT/VF and SCD by decreasing dispersion of repolarization and ventricular arrhythmias. Compared to placebo, DS lowered resting heart rate, preserved chronotropic competency during transient β-adrenergic challenge, and improved heart rate variability and cardiac function. Inhibition of RyR2 hyperactivity with dantrolene mitigates the vicious cycle of sarcoplasmic Ca2+ leak-induced increases in diastolic Ca2+ and ROS-mediated RyR2 oxidation, thereby reducing repolarization lability and protecting against VT/VF/SCD. Moreover, the consequent increase in sarcoplasmic Ca2+ load improves contractile function. These potentially life-saving effects of RyR2 inhibition warrant further investigation, such as clinical studies of repurposing dantrolene as a potential new therapy for heart failure and/or SCD.

Improvements in Heart Rate Variability among Dementia Family Caregivers Receiving a Home‐Visit Based Intervention: Preliminary Results from a Randomized Controlled Trial

AbstractBackgroundEmotional stress of family caregivers of persons with dementia (PWD) is often a topic of concern, as many experience negative health outcomes resulting from their years‐long caregiving role. A home‐visit based educational intervention focused on improving caregiving skills and managing stress was delivered to ethnically diverse dementia family caregivers in California in their preferred language. Previously, survey data were used to evaluate caregivers’ stress and well‐being. However, there might be limitations in using survey instruments to measure stress among diverse caregivers with limited English proficiency. Data collected via wearable technology (e.g., smartrings) can objectively measure stress in the form of Heart Rate Variability (HRV). We examined the intervention’s effect on stress levels measured by HRV among diverse dementia family caregivers using wearable technology.MethodsThe study design was a randomized controlled trial. Family caregivers of community dwelling PWD identifying as either Korean, Vietnamese, Hispanic/Latino, or Non‐Hispanic White were recruited through community outreach. Participants were randomly assigned with a 2:1 ratio to either the intervention group (IG) receiving language‐specific home‐visit based education or the attention control group (AG) receiving only care resource information. All participants wore smartrings monitoring HRV for 3 months. We used linear mixed models to assess the differences in HRV between the two groups using random intercept and slope for intervention, controlling for the covariates (age, gender, relationship, cohabitation, ethnicity, education).ResultsHRV data was collected from 59 caregivers (69% IG and 31% AG). Demographics included: 20 Korean (33.9%), 17 Vietnamese (28.8%), 10 Hispanic (17%), 12 Non‐Hispanic White (20.3%); 32 spouses (54%), 27 off‐spring (46%); 45 females (76%), ages 34 to 87 years (mean = 65.3, SD = 13.6). The linear mixed models showed a significant improvement in stress (higher HRV indicating better stress management) among IG caregivers compared to the AG caregivers over time (Beta coefficient = .079, P‐value = .032).ConclusionsMeasuring stress using smartrings was feasible and effective to track stress levels among diverse caregivers. Preliminary analyses suggest the home‐visit based intervention may have a positive effect on stress in ethnically diverse family caregivers of PWD compared to those only provided with care resource information.

The Use of Biofeedback Training Techniques for Improving Heart Rate Variability Scores and Achievements in Science Subjects among Primary School Students

The Use of Biofeedback Training Techniques for Improving Heart Rate Variability Scores and Achievements in Science Subjects among Primary School Students

The pilot study of reminder focused positive psychiatry body mind intervention on improving heart rate variability and autonomous nervous system reactivity in adults with posttraumatic stress disorder

The pilot study of reminder focused positive psychiatry body mind intervention on improving heart rate variability and autonomous nervous system reactivity in adults with posttraumatic stress disorder

Acute nasal breathing lowers diastolic blood pressure and increases parasympathetic contributions to heart rate variability in young adults.

There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect cardiovascular health. It is unknown whether the route of breathing (nasal vs. oral) affects prognostic cardiovascular variables. Because nasal breathing can improve other physiological variables (e.g., airway dilation), we hypothesized that nasal compared with oral breathing would acutely lower blood pressure (BP) and improve heart rate variability (HRV) metrics. We tested 20 adults in this study [13 females/7 males; age: 18(1) years, median (IQR); body mass index: 23 ± 2 kg·m-2, means ± SD]. We compared variables between nasal- and oral-only breathing (random order, five min each) using paired, two-tailed t tests or Wilcoxon signed-rank paired tests with significance set to P < 0.05. We report the median (interquartile range) for diastolic BP and means ± SD for all other variables. We found that nasal breathing was associated with a lower mean BP (nasal: 84 ± 7 vs. oral: 86 ± 5 mmHg, P = 0.006, Cohen's d = 0.70) and diastolic BP [nasal: 68(8) vs. oral: 72(5) mmHg, P < 0.001, Rank-biserial correlation = 0.89] but not systolic BP (nasal: 116 ± 11 vs. oral: 117 ± 9 mmHg, P = 0.48, Cohen's d = 0.16) or heart rate (HR; nasal: 74 ± 10 vs. oral: 75 ± 8 beats·min-1, P = 0.90, Cohen's d = 0.03). We also found that nasal breathing was associated with a higher high-frequency (HF) contribution to HRV (nasal: 59 ± 19 vs. oral: 52 ± 21%, P = 0.04, Cohen's d = 0.50) and a lower low frequency-to-HF ratio at rest (nasal: 0.9 ± 0.8 vs. oral: 1.2 ± 0.9, P = 0.04, Cohen's d = 0.49). These data suggest that nasal compared with oral breathing acutely 1) lowers mean and diastolic BP, 2) does not affect systolic BP or heart rate, and 3) increases parasympathetic contributions to HRV.NEW & NOTEWORTHY There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect prognostic cardiovascular variables. However, the potential effects of the breathing route on prognostic cardiovascular variables are unclear. These data suggest that nasal compared with oral breathing 1) lowers mean and diastolic blood pressure (BP), 2) does not affect systolic BP or heart rate (HR), and 3) increases parasympathetic contributions to heart rate variability (HRV). These data suggest that acute nasal breathing improves several prognostic cardiovascular variables.

3.70 The Pilot Study of Reminder-Focused Positive Psychiatry Body-Mind Intervention on Improving Heart Rate Variability and Autonomous Nervous System Reactivity in Individuals With PTSD

3.70 The Pilot Study of Reminder-Focused Positive Psychiatry Body-Mind Intervention on Improving Heart Rate Variability and Autonomous Nervous System Reactivity in Individuals With PTSD

Six months of resistance training improves heart rate variability in the elderly.

Heart rate variability is a non-invasive method of assessing global health through the analysis of the autonomous centralnervous system, including both the sympathetic and parasympathetic systems. The aim of this study was to evaluate the effect of resistance training on heart rate variability at rest in elderly individuals undergoing six months of resistance training with progressive loads. Training reduced the body fat percentage of the volunteers (pre: 39.39 ± 7.21 vs post: 34.97 ± 6.40%; p = 0.0069). There was also a significant reduction in the low-frequency index (pre: 69621.50 ± 9817.28 vs post: 54210.50 ± 14903.94; p = 0.0322) and a significant increase in the high-frequency index (pre: 30308.00 ± 9857.86 vs post: 45627.10 ± 14838.80; p = 0.0326). We concluded that sixmonths of resistance training with progressive loads were beneficial for heart rate variability and reduced the body fat percentage in the elderly.

Pilot study shows skin-to-skin care with parents improves heart rate variability in preterm infants in the neonatal intensive care unit.

Skin-to-skin care in the newborn intensive care unit typically lasts for short periods of time and enhances breastfeeding, attachment, and parental self-esteem. Heart rate variability (HRV) increases with gestational age and is a measure of maturation of parasympathetic vs. sympathetic autonomic nervous system activity. HRV measurements may be useful in capturing changes in autonomic regulation in response to skin-to-skin care. To analyze the effects of skin-to-skin care on HRV in preterm infants receiving respiratory support. We hypothesized that skin-to-skin care would result in a more mature pattern of parasympathetic activity. In this prospective crossover study, infants <30 weeks' gestation and 1-6 weeks postnatal age had HRV recorded for 30 min before, during, and after skin-to-skin care sessions. HRV characteristics analyzed included the standard deviation of the normal-to-normal interval (SDNN), the root mean squared of successive differences of normal-to-normal intervals (RMSSD), and the standard deviation of decelerations (SDDec). 10 infants between 25 5/7-29 6/7 weeks gestational age and 7-41 days postnatal age completed 22 sessions while receiving respiratory support (positive pressure ventilation or nasal cannula oxygen). Two measures of HRV (SDNN and RMSSD) were significantly decreased by the end of the skin-to-skin sessions, compared to pre-session values. SDNN decreased from a median of 10.44 ms before the session to 6.70 ms after being placed back in bed (p < 0.05), with RMSSD decreasing from a median of 6.80 ms before the session to 4.32 ms while being held at the end of 30 min (p < 0.05). Skin-to-skin care with a parent resulted in a more mature autonomic nervous system pattern in preterm infants receiving respiratory support, suggesting physiologic benefit for the infant. No adverse events were seen during any session.

Abstract P342: Acute Nasal Breathing Lowers Blood Pressure And Increases Parasympathetic Contributions To Heart Rate Variability In Young Adults

Introduction: Interest is growing in how breathing pace, pattern, and training (e.g., device-assisted or -resisted breathing) affect prognostic cardiovascular variables (e.g., blood pressure (BP)). Nasal breathing increases bronchodilation via airway epithelium nitric oxide production, increases diaphragmatic movement, and reduces accessory inspiratory muscle recruitment. Despite these changes, the effect of nasal compared with oral breathing (i.e., breathing route) on prognostic cardiovascular variables is unclear. Hypothesis: We hypothesized that nasal compared with oral breathing would acutely lower BP and improve heart rate variability (HRV) metrics. Methods: We tested 20 young healthy adults in this study (13 Female/7 Male; age: 18 [1] years, median [IQR]; body mass index: 23 ± 2 kg•m -2 , screening systolic / diastolic BP 116 ± 12 / 67 ± 7 mmHg mean ± SD). Participants self-selected their breathing rate during a five-minute ‘run-in’ period. Using a metronome, their breathing rate was fixed during two subsequent (random order) five-minute resting periods with nasal and oral breathing while we measured brachial BP and HRV metrics via ECG. We compared data between conditions using a Wilcoxon signed-rank paired test (data presented as median [IQR]) or using paired, two-tailed t-tests (data presented as mean ± SD). We set the significance to p &lt;0.05. Results: Nasal breathing lowered mean (nasal: 84 ± 7 vs. oral: 86 ± 5 mmHg, p =0.006, Cohen’s d =0.70) and diastolic (nasal: 68 [8] vs. oral: 72 [5] mmHg, p &lt;0.001, Rank-biserial correlation=0.89), but not systolic (nasal: 116 ± 11 vs. oral: 117 ± 9 mmHg, p =0.48, Cohen’s d =0.16) BP. Nasal breathing also raised the High-Frequency contribution to HRV (nasal: 59 ± 19 vs. oral: 52 ± 21 %, p =0.04, Cohen’s d =0.50) and lowered the Low-Frequency to High-Frequency ratio (nasal: 0.9 ± 0.8 vs. oral: 1.2 ± 0.9, p =0.04, Cohen’s d =0.49), suggesting a greater parasympathetic contribution to HRV. There were no differences between conditions for heart rate ( p= 0.90) or time-domain HRV metrics ( ps ≥0.07; e.g., the standard deviation of NN intervals). Conclusion: These data suggest that nasal compared with oral breathing acutely lowers mean and diastolic BP as well as potentially increases parasympathetic contributions to HRV.

ALIVE Biofeedback HRV training for Treating Insomnia: A Pilot Randomized Controlled Study.

Background: Insomnia is a common sleep disorder that affects a large portion of the population. While several treatments are available, such as medication and cognitive-behavioral therapy, some individuals may not respond well to these treatments. Biofeedback, a technique that provides individuals with real-time feedback on their physiological responses, has shown promise in treating insomnia. This study aimed to investigate the effectiveness of ALIVE biofeedback HRV training in treating insomnia. Methodology: This pilot study utilized a randomized controlled trial design to investigate the efficacy of ALIVE biofeedback intervention in individuals diagnosed with insomnia. A total of 60 participants with insomnia were randomly assigned to either the ALIVE biofeedback or control group. The ALIVE biofeedback group received a six week intervention involving relaxation techniques, deep breathing exercises, and mindfulness meditation using the ALIVE Pioneer system for heart rate variability (HRV) biofeedback training. The control group received standard care for insomnia. Outcome measures included HRV parameters, blood pressure, the Pittsburgh Sleep Quality Index Japanese version (PSQI J), and the Insomnia Severity Index (ISI). Results: The ALIVE biofeedback group showed significant improvements in heart rate variability (HRV) parameters, including increased SDNN and RMSSD and high-frequency power (HF) after the 6-week intervention. The control group did not display significant changes in HRV. Additionally, the ALIVE biofeedback group significantly decreased diastolic blood pressure. Regarding sleep outcomes, the ALIVE biofeedback group reported increased sleep duration and decreased sleep disturbances, as indicated by the PSQI-J scores. Furthermore, participants in the ALIVE biofeedback group significantly improved their ISI scores. These findings suggest that the ALIVE biofeedback intervention can potentially improve HRV, blood pressure, sleep quality, and insomnia severity in individuals with insomnia. Conclusion: It is concluded from the study results that the ALIVE biofeedback training is a non-invasive and effective treatment for insomnia.

Interleukin 6 (IL-6) Regulates GABAA Receptors in the Dorsomedial Hypothalamus Nucleus (DMH) through Activation of the JAK/STAT Pathway to Affect Heart Rate Variability in Stressed Rats.

The dorsomedial hypothalamus nucleus (DMH) is an important component of the autonomic nervous system and plays a critical role in regulating the sympathetic outputs of the heart. Stress alters the neuronal activity of the DMH, affecting sympathetic outputs and triggering heart rate variability. However, the specific molecular mechanisms behind stress leading to abnormal DMH neuronal activity have still not been fully elucidated. Therefore, in the present study, we successfully constructed a stressed rat model and used it to investigate the potential molecular mechanisms by which IL-6 regulates GABAA receptors in the DMH through activation of the JAK/STAT pathway and thus affects heart rate variability in rats. By detecting the c-Fos expression of neurons in the DMH and electrocardiogram (ECG) changes in rats, we clarified the relationship between abnormal DMH neuronal activity and heart rate variability in stressed rats. Then, using ELISA, immunohistochemical staining, Western blotting, RT-qPCR, and RNAscope, we further explored the correlation between the IL-6/JAK/STAT signaling pathway and GABAA receptors. The data showed that an increase in IL-6 induced by stress inhibited GABAA receptors in DMH neurons by activating the JAK/STAT signaling pathway, while specific inhibition of the JAK/STAT signaling pathway using AG490 obviously reduced DMH neuronal activity and improved heart rate variability in rats. These findings suggest that IL-6 regulates the expression of GABAA receptors via the activation of the JAK/STAT pathway in the DMH, which may be an important cause of heart rate variability in stressed rats.

Physical Exercise Effects on Cardiovascular Autonomic Modulation in Postmenopausal Women-A Systematic Review and Meta-Analysis.

The cardioprotective effect of physical exercise has been demonstrated in several studies. However, no systematic or updated analysis has described the effects of physical exercise on cardiovascular autonomic modulation in postmenopausal women. to describe the effects of physical exercise on cardiovascular autonomic modulation in postmenopausal women. The Scopus, PubMed, and Embase databases were searched for randomized clinical trials published between January 2011 and December 2021, and regarding the effects of physical exercise on cardiovascular autonomic modulation in postmenopausal women. Two independent authors processed the citations. The methodological quality was evaluated using the PEDRo scale. Of the 91 studies identified, only 8 met the inclusion criteria, of which 7 had fair or poor methodological quality. The analyzed studies investigated the effects of functional training, whole-body vibration, muscular resistance, stretching, and aerobic exercises performed at home or at the gym. The majority of these exercise modalities showed improvements in heart-rate variability (HRV) indices and in the low-frequency band of blood pressure variability. The meta-analysis shows that exercise increased the standard deviation of instantaneous beat-to-beat variability (SD1) (mean difference (MD) = 3.99; 95% confidence interval (CI) = 1.22 to 6.77, n = 46; I2: 0%) and the standard deviation of long-term variability (SD2) (MD = 11.37; 95% CI = 2.99 to 19.75; n = 46; I2: 0%). Aerobic exercise and some nonconventional training modalities may have beneficial effects on cardiovascular autonomic modulation in postmenopausal women. More high-quality studies are still needed to further confirm their efficacy and safety.

The successful use of Cytoflavin in the patient with postaveny syndrome

A clinical observation of the use of Cytoflavin according to a two-stage scheme (10.0 ml intravenously drip per 200 ml of 0.9% sodium chloride solution for 10 days, followed by a transition to a tablet form of 2 tablets 2 times/day for 25 days) in a patient with postcovid syndrome with pronounced vegetative and neurocognitive disorders. The effectiveness of therapy was confirmed by an improvement in heart rate variability and a decrease in the severity of depression, anxiety (on the HADS scale) and the level of autonomic dysfunction (on the COMPASS-31 scale). The significant changes in levels of fatigue (on a scale MFI) is not marked. The obtained results can serve as a basis for further research.

Dapagliflozin Improves Cardiac Autonomic Function Measures in Type 2 Diabetic Patients with Cardiac Autonomic Neuropathy.

Cardiac autonomic neuropathy is a frequent complication of type 2 diabetes mellitus. Cardiac autonomic neuropathy, in which sympathetic tone predominates over parasympathetic activity, increases both cardiovascular morbidity and mortality and unfortunately has no definitive treatment. Sodium-glucose cotransporter-2 inhibitors have been suggested to reduce sympathetic nervous system activity, based on the results from previous studies. In this study, we aimed to investigate the effect of 24-week treatment with dapagliflozin, a sodium-glucose cotransporter-2 inhibitor, on cardiac autonomic function measures in patients with type 2 diabetes mellitus and cardiac autonomic neuropathy. Dapagliflozin 10 mg/day (n=42) or non-sodium-glucose cotransporter-2 inhibitor oral antidiabetic(s) (n=38) was added to the treatment of patients whose glycemic control could not be achieved with existing treatments. The patients with definite or confirmed cardiac autonomic neuropathy diagnosed by cardiovascular autonomic reflex tests underwent 24-hour Holter-electrocardiogram recordings to obtain heart rate variability and heart rate turbulence parameters before starting additional medication and after a 24-week treatment period. In-group analyses showed that dapagliflozin 10 mg/day for 24 weeks improved heart rate variability and heart rate turbulence parameters and decreased the frequency of ventricular premature beats relative to their baseline values. No such findings were observed in the control group despite similar glycemic control. Comparisons between dapagliflozin group and the control group showed that these effects of dapagliflozin were significantly better than non-sodium-glucose cotransporter-2 inhibitor oral antidiabetics. Dapagliflozin improves measures of cardiac autonomic function compared to the control group in type 2 diabetic patients with cardiac autonomic neuropathy. This intergroup benefit, demonstrated for the first time, may be promising for the regression of cardiac autonomic neuropathy with sodium-glucose cotransporter-2 inhibitors.

Ultrasound-guided injection of botulinum toxin type A blocks cardiac sympathetic ganglion to improve cardiac remodeling in a large animal model of chronic myocardial infarction

Strategies to improve various cardiovascular diseases by blocking cardiac sympathetic ganglion have been increasingly available currently. Botulinum toxin type A (BTA), a typical neurotoxin, has been shown to block neural transmission in a safe and long-lasting manner. The aim of the present preclinical study was to assess the efficacy of BTA microinjection to alleviate cardiac remodeling after chronic myocardial infarction (MI) by blocking cardiac sympathetic ganglion in a canine model. Beagles were randomly divided into a control group (saline microinjection with sham surgery), an MI group (saline microinjection with MI), and an MI + BTA group (BTA microinjection with MI). Ultrasound-guided percutaneous BTA or saline injection into the left stellate ganglion (LSG) was performed followed by MI induction via left anterior descending artery occlusion (LADO) or sham surgery. After 30 days, electrocardiography, Doppler echocardiography, LSG function, neural activity, and ventricular electrophysiological detection were performed in all experimental dogs. At the end, LSG and ventricular tissues were collected for further detection. BTA treatment significantly inhibited LSG function and neural activity and improved heart rate variability. Additionally, BTA application alleviated ventricular remodeling, ameliorated cardiac function, and prevented ventricular arrhythmias after 30-day chronic LADO-induced MI. Ultrasound-guided percutaneous microinjection of BTA can block cardiac sympathetic ganglion to improve cardiac remodeling in a large animal model of chronic LADO-induced MI. Ultrasound-guided BTA microinjection has potential for clinical application as a novel cardiac sympathetic ganglion blockade strategy for MI.