A comprehensive review of heart rate variability as an indicator in the regulation of the autonomic nervous system by acupuncture:a bibliometric analysis

This study sought to conduct a bibliometric analysis of acupuncture studies focusing on heart rate variability(HRV)and to investigate the correlation between various acupoints and their effects on HRV by utilizing association rule mining and network analysis.A total of 536 publications on the topic of acupuncture studies based on HRV.The disease keyword analysis revealed that HRV-related acupuncture studies were mainly related to pain,inflammation,emotional disorders,gastrointestinal function,and hypertension.A separate analysis was conducted on acupuncture prescriptions,and Neiguan(PC6)and Zusanli(ST36)were the most frequently used acupoints.The core acupoints for HRV regulation were identified as PC6,ST36,Shenmen(HT7),Hegu(LI4),Sanyinjiao(SP6),Jianshi(PC5),Taichong(LR3),Quchi(LI11),Guanyuan(CV4),Baihui(GV20),and Taixi(KI3).Additionally,the research encompassed 46 reports on acupuncture animal experiments conducted on HRV,with ST36 being the most frequently utilized acupoint.The research presented in this study offers valuable insights into the global research trend and hotspots in acupuncture-based HRV studies,as well as identifying frequently used combinations of acupoints.The findings may be helpful for further research in this field and provide valuable information about the potential use of acupuncture for improving HRV in both humans and animals.

Quran memorisation and heart rate variability:How do they correlate?

BACKGROUND Heart rate variability(HRV)was shown to be affected by performing religious activities.AIM To examine the relationship between the level of Quran(the holy book of Muslims)memorisation and HRV among teenagers.METHODS This experimental study included 16 Tahfiz students and 16 non-Tahfiz students(n=32).The HRV was measured in three tasks:Recalling familiar verses,memorising new verses,and recalling the newly memorised verses of the Quran.HRV analysis was done using these parameters:Standard deviation of N-N(heartbeat peak)interval;low frequency(LF);high frequency(HF)and LF/HF ratio.RESULTS There were significant differences between tasks for all parameters(P<0.05).However,between the groups,only the LF/HF ratio had significant differences,with F=5.04,P<0.05.Pearson correlation showed a moderate positive correlation between the number of pages memorised and the LF/HF ratio(r=0.61,P<0.05).CONCLUSION Quran memorisation increased the HRV and our results suggested that this activity could be developed as an effective sympathovagal modulation training activity.

Stress prevention by modulation of autonomic nervous system (heart rate variability): A preliminary study using transcranial direct current stimulation

Introduction: Transcranial Direct Current Stimulation (tDCS) is a non-invasive, technique for brain stimulation. Anodal stimulation causes neuronal depolarisation and long-term potentiation, while cathodal stimulation causes hyperpolarisation and long-term depression. Stressors are associated with an increase in sympathetic cardiac control, a decrease in parasympathetic control, or both. Associated with these reactions is a frequently reported increase in Low Frequency (LF) Heart Rate Variability (HRV), a decrease in High Frequency (HF) power, and/or an increase in the LF/HF ratio. Objectives and aims: The present work aims to explore the tDCS potential in the modulation of the Autonomic Nervous System (ANS), through indirect stimulation of Anterior Cingulate Cortex (ACC). Methods: Two subjects, a 39 year old female and a 49 year old male, gave informed consent. Saline soaked synthetic sponges involving two, thick, metalic (stainless steel) rectangles, with an area of 25 cm2 each have been used as electrodes, connected to Iomed Phoresor II Auto device. It has been delivered a 2 mA current, for 20 minutes, over the left Dorsolateral Prefrontal Cortex (DLPFC) (Anode). Spectrum analysis (cStress software) of HRV has been performed before and after tDCS administration. Results: The female/male subject results of LF power, HF power and LF/HF ratio, before tDCS administration, were, respectively: 50.1 nu/60 nu, 46.1 nu/21.7 nu and 1.087/2.771;and, after tDCS administration, respectively: 33.5 nu/52.7 nu, 47.6 nu/ 22.8 nu and 0.704/2.312. Conclusions: tDCS over the left DLPFC (left ACC) increased parasympathetic activity and decreased sympathetic activity, suggesting the importance of tDCS in the management of stress-related disorders.

Does heart rate variability correlate with long-term prognosis in myocardial infarction patients treated by early revascularization?

AIMTo assess the prevalence of depressed heart rate variability (HRV) after an acute myocardial infarction (MI), and to evaluate its prognostic significance in the present era of immediate reperfusion.METHODSTime-domain HRV (obtained from 24-h Holter recordings) was assessed in 326 patients (63.5 ± 12.1 years old; 80% males), two weeks after a complicated MI treated by early reperfusion: 208 ST-elevation myocardial infarction (STEMI) patients (in which reperfusion was successfully obtained within 6 h of symptoms in 94% of cases) and 118 non-ST-elevation myocardial infarction (NSTEMI) patients (percutaneous coronary intervention was performed within 24 h and successful in 73% of cases). Follow-up of the patients was performed via telephone interviews a median of 25 mo after the index event (95%CI of the mean 23.3-28.0). Primary end-point was occurrence of all-cause or cardiac death; secondary end-point was occurrence of major clinical events (MCE, defined as mortality or readmission for new MI, new revascularization, episodes of heart failure or stroke). Possible correlations between HRV parameters (mainly the standard deviation of all normal RR intervals, SDNN), clinical features (age, sex, type of MI, history of diabetes, left ventricle ejection fraction), angiographic characteristics (number of coronary arteries with critical stenoses, success and completeness of revascularization) and long-term outcomes were analysed.RESULTSMarkedly depressed HRV parameters were present in a relatively small percentage of patients: SDNN < 70 ms was found in 16% and SDNN < 50 ms in 4% of cases. No significant differences were present between STEMI and NSTEMI cases as regards to their distribution among quartiles of SDNN (χ2 =1.536, P = 0.674). Female sex and history of diabetes maintained a significant correlation with lower values of SDNN at multivariate Cox regression analysis (respectively: P = 0.008 and P = 0.008), while no correlation was found between depressed SDNN and history of previous MI (P = 0.999) or number of diseased coronary arteries (P = 0.428) or unsuccessful percutaneous coronary intervention (PCI) (P = 0.691). Patients with left ventricle ejection fraction (LVEF) < 40% presented more often SDNN values in the lowest quartile (P < 0.001). After > 2 years from infarction, a total of 10 patients (3.1%) were lost to follow-up. Overall incidence of MCE at follow-up was similar between STEMI and NSTEMI (P = 0.141), although all-cause and cardiac mortality were higher among NSTEMI cases (respectively: 14% vs 2%, P = 0.001; and 10% vs 1.5%, P = 0.001). The Kaplan-Meier survival curves for all-cause mortality and for cardiac deaths did not reveal significant differences between patients with SDNN in the lowest quartile and other quartiles of SDNN (respectively: P = 0.137 and P = 0.527). Also the MCE-free survival curves were similar between the group of patients with SDNN in the lowest quartile vs the patients of the other SDNN quartiles (P = 0.540), with no difference for STEMI (P = 0.180) or NSTEMI patients (P = 0.541). By the contrary, events-free survival was worse if patients presented with LVEF < 40% (P = 0.001).CONCLUSIONIn our group of patients with a recent complicated MI, abnormal autonomic parameters have been found with a prevalence that was similar for STEMI and NSTEMI cases, and substantially unchanged in comparison to what reported in the pre-primary-PCI era. Long-term outcomes did not correlate with level of depression of HRV parameters recorded in the subacute phase of the disease, both in STEMI and in NSTEMI patients. These results support lack of prognostic significance of traditional HRV parameters when immediate coronary reperfusion is utilised.

A Study into Blood Flow, Heart Rate Variability, and Body Surface Temperature While Listening to Music

In this study we examined the relaxing effects of listening to music on a total of 12 women aged from their 20s to their 40s by measuring their blood flow, heart rate variability, and their body surface temperature. As a result, We found that there was a tendency for the volume of blood flow to the fingertips to significantly increase when listening to classical music, but there was a variety of changes in blood flow between each age group for healing music and J-Pop music. When measuring heart rate it was found that the LF/HF value, which is an index for the autonomic nervous system which shows tension and stress, fell significantly when listening to each type of music. Lastly, there was a trend for body surface temperature to rise when listening to classical or healing music, a rise which was particularly significant when listening to healing music. This study shows that a relaxing effect can be expected for all indices when listening to classical music. However, for healing music and J-Pop, personal musical preferences seemed to have an effect and the results were varied.

Changes in Heart Rate Variability and Effects on POMS by Whether or Not Soil Observation Was Performed

Introduction: The effects of performing soil observation on autonomic nerve function (ANS) and the profile of mood states (POMS) particularly for upsurge of sentiment were studied table. Methods: The subjects were divided into two groups: Group A with soil observation, and Group B without it. Soil observation was performed by smelling soil, touching the soil and other ways. Evaluation was made using heart rate change variability, POMS and visual analog scale (VAS). Results: Group A showed an increase in high frequency (HF) and the LF (low frequency)/HF ratio and a decrease in heart rate, leading to activating the functions of the parasympathetic nervous system. VAS values for “not comforted at all” indicated that the scale was lower in Group A than in Group B. In POMS, a factor of “vigor” became lower in Group B than in Group A. Discussion: It was suggested that soil observation was effective in bringing people to a state of physiological and mental relaxation and reducing stress because it raised the degree of being comforted, increased HF, decreased the heart rate and activated the parasympathetic nervous system. Conclusions: By performing soil observation, the heart rate decreased, HF increased and an upsurge sentiment became normalized.

Modeling of Heart Rate Variability Using Time-Frequency Representations

The heart rate variability signal is highly correlated with the respiration even at high workload exercise.It is also known that this phenomenon still exists during increasing exercise.In the current study,we managed to model this correlation during increasing exercise using the time varying integral pulse frequency modulation(TVIPFM)model that relates the mechanical modulation(MM)to the respiration and the cardiac rhythm.This modulation of the autonomic nervous system(ANS)is able to simultaneously decrease sympathetic and increase parasympathetic activity.The TVIPFM model takes into consideration the effect of the increasing exercise test,where the effect of a time-varying threshold on the heart period is studied.Our motivation is to analyze the heart rate variability(HRV)acquired by time varying integral pulse frequency modulation using time frequency representations.The estimated autonomic nervous system(ANS)modulating signal is filtered throughout the respiration using a time varying filtering,during exercise stress testing.And after summing power of the filtered signal,we compare the power of the filtered modulation of the ANS obtained with different time frequency representations:smoothed pseudo Wigner–Ville representation,spectrogram and their reassignments.After that,we used a student t-test p<0.01 to compare the power of heart rate variability in the frequency band of respiration and elsewhere.

Evaluation with Heart Rate Variability for the Treatment Effect of Aminophylline in Patients with Bradycardia after Cervical Spinal Cord Injury: A Preliminary Study

After cervical spinal cord injury (SCI), the autonomic nervous system (ANS) becomes impaired and then, bradycardia can develop. In view of this, we performed to prescribe aminophylline as pharmacotherapy for bradycardia. The study population consisted of 36 patients with cervical SCI. Bradycardia developed in 20 patients (55.6%), of these patients, 8 showed spontaneous recovery. Twelve patients had persistent bradycardia, therefore, aminophylline was administered at 0.5 mg/kg/hr by intravenous infusion. Their average heart rate increased within 24 hours after the start of infusion. In heart rate variability analysis for 7 preliminarily selected patients, the spectral waveforms of “oligowave type” indicating ANS impairment tended to appear in relatively early phase after injury (i.e., 2 days to 2 weeks after injury), whereas “normal type” was observed in the late phase (i.e., at 4 weeks). “Sympathetic block type” was observed throughout the follow-up period (2 days to 4 weeks). “Sympathetic block type” was also observed in a non-bradycardic patient on day 2. These results underscore the importance of treating ANS impairment with aminophylline while keeping in mind that bradycardia can occur even in post-SCI patients without clinical manifestations.

The association of salivary alpha-amylase, heart rate variability, and psychological stress on objectively measured sleep behaviors among college students

Objective:This study aimed to evaluate sleep behaviors among college students,to assess salivary alpha-amylase(sAA)and heart rate variability(HRV)in association with stress,and to investigate sleep-related factors including sAA,HRV,and stress among them.Methods:Saliva samples for sAA assessment and HRV measurements in the supine position were taken between 3 PM and 6 PM.The level of prolonged psychological stress for the previous week was evaluated using the Korean version of the Global Assessment of Recent Stress(GARS-K),and sleep behaviors were assessed using an actigraphy device.Results:A total of 86 healthy college students participated in this study.Sleep behaviors of the college students were not good,with 84%sleep efficiency(SE)and 62.7 min wake after sleep onset(WASO).The average sAA level was 65.8 U/mL in the participants.Although neither the sAA level nor HRV indices were significantly correlated with prolonged psychological stress,decreased normalized high frequency(nHF)on HRV was independently associated with a higher level of stress when adjusted for age and sex.Higher stress(r=-0.276,P=0.011)and lower sAA(r=0.266,P=0.030)had significant correlations with shorter time in bed;however,it was sAA that was independently associated with time in bed(β=0.244,p=0.044).Decreased nHF(β=0.245,P=0.027)and higher body mass index(BMI)(β=-0.224,P=0.043)were independently related to and poorer SE.Conclusions:Poor sleep behaviors were associated with decreased parasympathetic activity,a physiological change to psychological stress,rather than with psychological stress itself among college students.Thus,sAA and HRV should be considered as significant factors for impaired sleep behaviors in relation to psychological stress.

Effects of Yoga Exercises on Heart Rate Variability Parameters and Perceived Stress in Adolescent Students with High Score in Perceived Stress

Introduction: Hatha Yoga is a widely used form of holistic mind-body therapy for promoting health, and disease prevention like cardiovascular risks and part of treatment for neurological disorders. Objective: The aim of this study was to evaluate the effect of Hatha yoga on the autonomic nervous system by tracking acute changes in the time-domain and frequency-domain metrics of heart rate variability (HRV) in healthy International Baccalaureate students arranged in 3 different groups. Methods: The prospective interventional study was conducted among adolescent students in China. Thirty-six adolescent students were divided in three groups: 12 Hatha yoga experimental group participants;a control group of 12 students without participation in any activity and a recreational sport group of 12 other students. Outcomes measured were HRV parameters such as SDNN, RMSSD LF, HF, and LF/HF. Also, a Competitive State Anxiety Inventory-2 was used to measure stress and anxiety score in terms of Cognitive stress, Somatic Stress and Self Confidence. Results: Compared to baseline values, the Hatha yoga experiment group demonstrated a significant increase in HRV indices: SDNN 87.62 ± 13.89 (>0.0001) and RMSDD 86.61 ± 7.78 (>0.0001) respectively. In contrast it was documented after the 3 weeks of exposure to yoga training a statistically significant decrease in the frequency domain of LF 1911.53 ± 882.15 (0.0464) compared to baseline values. After completion of intervention the yoga experiment group HF (ms2) values were increased 3430.40 ± 858.38 (>0.0001). Decrease and increase in the HF (ms2) in the control and Hatha yoga group were statistically significant after following Hatha yoga. Cognitive anxiety 18.08 ± 6.30 (>0.0001) and Somatic anxiety 17.50 ± 6.33 (>0.0001) decreased after intervention with yoga and self-confidence increased significantly 32.50 ± 1.17 (>0.0001). Conclusions: The investigation showed a significant increase of HRV parameters and cardiac autonomic function as a result of exposure to Yoga practice. Also, there was significant evidence of decrease in cognitive stress and somatic stress;increased values of self-confidence at the end of three weeks yoga exposure in comparison to the baseline values.

High frequency heart rate variability evoked by repetitive transcranial magnetic stimulation over the medial prefrontal cortex: A preliminary investigation on brain processing of acute stressor-evoked cardiovascular reactivity

Introduction: Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for brain stimulation. Repetitive TMS (rTMS) over the medial Prefrontal Cortex (mPFC), Broadman Area 10 (BA10) may stimulate transynaptically perigenual Anterior Cingulate Cortex (pACC, BA 33), insula, amigdala, hypothalamus and connected branches of the Autonomic Nervous System (ANS) involved in stressorevoked cardiovascular reactivity. Stressors are associated with an increase in sympathetic cardiac control, a decrease in parasympathetic control, or both, and, consequently, an increase in systolic/stroke volume, total vascular impedance/resistance and heart rate, a decrease of baroreflex sensitivity, i.e., an increase in blood pressure/arterial tension. Objectives and Aims: The present work aims, using TMS and accordingly to Gianaros modeling, based on functional neuroimaging studies and previous neuroanatomical data from animal models, to probe the connectivity of brain systems involved in stressor-evoked cardiovascular reactivity and to explore TMS potential as a tool for detection and stratification of individual differences concerning this reactivity and hemorreological risk factors correlated with the development of Coronary Heart Disease (CHD). Methods: Both subjects, a 52 years old male and a 40 years old female with previous increased Low Frequency (LF)/High Frequency (HF) Heart Rate Variability (HRV) ratios (respectively, 4.209/3.028) without decompensated cardiorespiratory symptoms, gave informed consent, and ethico-legal issues have been observed. Electroencephalographic (EEG) monitoring has been performed for safety purposes. Immediately after administration, over the mPFC, of 15 pulses of rTMS, during 60 second, with an inductive electrical current, at the stimulating coil, of 85.9 Ampère per μsecond and 66 Ampère per μsecond, respectively, for male and female subjects (a “figure-of-eight” coil and magnetic stimulator MagLite, Dantec/Medtronic, have been used), HRV spectrum analysis (cStress software) has been performed (during 5 minutes, in supine position). Results: In both subjects, LF power, HF power and LF/HF ratio results, before and after rTMS administration, pointed towards sympathetic attenuation and parasympathetic augmentation (respectively, in male/female subject: decreased LF power—65.1 nu/69.3 nu, before rTMS;56.1 nu/41.6 nu, after rTMS;increased HF power—15.5 nu/22.9 nu, before rTMS;30.9 nu/45.5 nu, after rTMS). Conclusions: In this preliminary investigation, the existence of a link between “mind” and heart’s function has been put in evidence, through a reversible “virtual” lesion, of brain systems involved in cardiovascular control, caused by TMS. Repetitive TMS over mPFC decreased brain function involved in stressorevoked cardiovascular reactivity, suggesting the importance of TMS in the management of stress-related cardiovascular disorders.

Influence of Acupuncture on Autonomic Balance in Adult Tinnitus Patients:An Exploratory Study

Acupuncture is an alternative therapy for tinnitus in clinical practice.The mechanism by which acupuncture can alleviate tinnitus is still unknown.Autonomic nervous system was reported to be responsible for tinnitus.The aim of this study was to explore the effect of acupuncture on autonomic balance in adult tinnitus patients.Thirty patients were randomly assigned into either the deep acupuncture(DA)group or the shallow acupuncture(SA)group.Each patient received 6 acupuncture sessions(a-f phase)over three weeks.Measures of heart rate variability and Tinnitus Handicap Inventory(THI)were obtained at baseline and after the sixth acupuncture session in all patients.The results showed that the low frequency/high frequency(LF/HF)pattern was increased at b-f phase until the sixth acupuncture session when compared with that at the first acupuncture session in DA group.However,it continuously increased at b-f phase in SA group even at the sixth acupuncture session,which was not significantly different from that at the first acupuncture session.The decrease in THI in DA group was greater than that in SA group after 3-week treatment(P=0.043).Our preliminary study suggests three-week deep acupuncture can improve tinnitus symptoms in adult tinnitus patients,which may be related to the regulation of autonomic nervous system balance.

Vitamin C ameliorated cardiac autonomic neuropathy in type 2 diabetic rats

BACKGROUND Vitamin C(VC)is a common antioxidant with cell protection potentials.However,its possible protective effect on cardiac autonomic nerves from diabetic induced insults is yet to be explored.AIM To investigate the effects of VC on diabetic cardiac autonomic neuropathy.METHODS Thirty male Wistar rats were equally grouped into control,diabetic and diabetic+VC.Type 2 diabetes was induced with fructose diet and alloxan.VC(1 g/kg)was administered for 4 wk via oral canula.Blood pressure and heart rate were measured non-invasively using tail flick blood pressure monitor.Spectral analysis of heart rate variability(HRV)was used to assess cardiac autonomic neuropathy.Blood was collected from the ocular sinus for biochemical analysis.Urethane(1 g/kg-ip)was used for anaesthesia prior to HRV and cervical dislocation to harvest hearts.Intracardiac autonomic nerve was assessed using tyrosine hydroxylase immunohistochemistry on fixed heart sections.RESULTS Results were analysed using ANOVA atα0.05.Unlike VC and control groups,diabetic rats showed significantly(P<0.0001)reduced HRV,increased heart-rate and blood pressure,initial increase in cardiac tyrosine hydroxylase activities at week-2 and sparse activity at week-4 of diabetes.Furthermore,apolipoprotein B,Oxidative stress and inflammatory markers were significantly(P<0.01)reduced in VC treated rats.CONCLUSION VC possesses cardio-autonomic nerve protective potential and ameliorates the symptoms of cardiac autonomic neuropathy in type 2 diabetes.The possible mechanisms via which VC exert these effects may be via downregulation of oxidative stress,inflammation and apolipoprotein B.

腹部推拿对阈下抑郁大学生自主神经功能调控的临床研究

目的:探究腹部推拿对阈下抑郁大学生自主神经功能的调控作用。方法:选取2022年9月~2023年12月于湖南中医药大学招募的阈下抑郁大学生64例,并随机分为腹部推拿组与对照组各32例;最终完成试验的受试者为,腹部推拿组31例,对照组29例。腹部推拿组以摩腹、按揉腹部、振腹三种手法进行操作,对照组则在腹部予以静止性触摸,每周一、三、五各干预1次,每次25 min,共6周。观察两组受试者干预前后及1个月随访时汉密尔顿抑郁量表17项版(HAMD-17)评分,干预前后心率变异性(HRV)时域指标SDNN、RMSSD、pNN50及频域指标VLF、LF、HF、LF/HF的变化,以及两组临床疗效。结果:治疗后,腹部推拿组患者HAMD-17评分较治疗前显著降低(P<0.01),对照组患者HAMD-17评分较治疗前降低(P<0.05),且腹部推拿组患者HAMD-17评分显著低于对照组(P<0.01);1个月随访时,腹部推拿组HAMD-17评分仍维持治疗后水平,且显著低于对照组(P<0.01):而对照组HAMD-17评分逐渐回升,与治疗前相比差异无统计学意义(P>0.05)。治疗后,腹部推拿组SDNN、RMSSD、pNN50较治疗前显著升高(P<0.01),对照组SDNN、RMSSD、pNN50较治疗前有升高趋势,但差异无统计学意义(P>0.05),且腹部推拿组SDNN、RMSSD、pNN50均高于对照组(P<0.01)。治疗后,腹部推拿组VLF、LF较治疗前升高(P<0.01)、HF较治疗前升高(P<0.05),LF/HF较治疗前降低(P<0.05);对照组VLF、LF、HF较治疗前有升高趋势,LF/HF较治疗前有降低趋势,但差异均无统计学意义(P>0.05);且腹部推拿组VLF、LF均显著高于对照组(P<0.01),HF高于对照组(P<0.05)、LF/HF低于对照组(P<0.05)。腹部推拿组总有效率高于对照组(P<0.01)。结论:腹部推拿能够改善抑郁情绪,并能调控自主神经功能,尤其是激活副交感神经。

Cardiac autonomic neuropathy in patients with diabetes mellitus

Cardiac autonomic neuropathy(CAN)is an often overlooked and common complication of diabetes mellitus.CAN is associated with increased cardiovascular morbidity and mortality.The pathogenesis of CAN is complex and involves a cascade of pathways activated by hyperglycaemia resulting in neuronal ischaemia and cellular death.In addition,autoimmune and genetic factors are involved in the development of CAN.CAN might be subclinical for several years until the patient develops resting tachycardia,exercise intolerance,postural hypotension,cardiac dysfunction and diabetic cardiomyopathy.During its sub-clinical phase,heart rate variability that is influenced by the balance between parasympathetic and sympathetic tones can help in detecting CAN before the disease is symptomatic.Newer imaging techniques(such as scintigraphy)have allowed earlier detection of CAN in the pre-clinical phase and allowed better assessment of the sympathetic nervous system.One of the main difficulties in CAN research is the lack of a universally accepted definition of CAN;however,the Toronto Consensus Panel on Diabetic Neuropathy has recently issued guidance for the diagnosis and staging of CAN,and also proposed screening for CAN in patients with diabetes mellitus.A major challenge,however,is the lack of specific treatment to slow the progression or prevent the development of CAN.Lifestyle changes,improved metabolic control might prevent or slow the progression of CAN.Reversal will require combination of these treatments with new targeted therapeutic approaches.The aim of this article is to review the latest evidence regarding the epidemiology,pathogenesis,manifestations,diagnosis and treatment for CAN.

Diabetes and cardiac autonomic neuropathy: Clinical manifestations, cardiovascular consequences, diagnosis and treatment

Cardiac autonomic neuropathy(CAN) is a frequent chronic complication of diabetes mellitus with potentially life-threatening outcomes. CAN is caused by the impairment of the autonomic nerve fibers regulating heart rate, cardiac output, myocardial contractility, cardiac electrophysiology and blood vessel constriction anddilatation. It causes a wide range of cardiac disorders, including resting tachycardia, arrhythmias, intraoperative cardiovascular instability, asymptomatic myocardial ischemia and infarction and increased rate of mortality after myocardial infarction. Etiological factors associated with autonomic neuropathy include insufficient glycemic control, a longer period since the onset of diabetes, increased age, female sex and greater body mass index. The most commonly used methods for the diagnosis of CAN are based upon the assessment of heart rate variability(the physiological variation in the time interval between heartbeats), as it is one of the first findings in both clinically asymptomatic and symptomatic patients. Clinical symptoms associated with CAN generally occur late in the disease process and include early fatigue and exhaustion during exercise, orthostatic hypotension, dizziness, presyncope and syncope. Treatment is based on early diagnosis, life style changes, optimization of glycemic control and management of cardiovascular risk factors. Medical therapies, including aldose reductase inhibitors, angiotensin-converting enzyme inhibitors, prostoglandin analogs and alpha-lipoic acid, have been found to be effective in randomized controlled trials. The following article includes the epidemiology, clinical findings and cardiovascular consequences, diagnosis, and approaches to prevention and treatment of CAN.

Cardiac autonomic neuropathy: Risk factors, diagnosis and treatment

Cardiac autonomic neuropathy(CAN)is a serious complication of diabetes mellitus(DM)that is strongly associated with approximately five-fold increased risk of cardiovascular mortality.CAN manifests in a spectrum of things,ranging from resting tachycardia and fixed heart rate(HR)to development of"silent"myocardial infarction.Clinical correlates or risk markers for CAN are age,DM duration,glycemic control,hypertension,and dyslipidemia(DLP),development of other microvascular complications.Established risk factors for CAN are poor glycemic control in type 1 DM and a combination of hypertension,DLP,obesity,and unsatisfactory glycemic control in type 2DM.Symptomatic manifestations of CAN include sinus tachycardia,exercise intolerance,orthostatic hypotension(OH),abnormal blood pressure(BP)regulation,dizziness,presyncope and syncope,intraoperative cardiovascular instability,asymptomatic myocardial ischemia and infarction.Methods of CAN assessment in clinical practice include assessment of symptoms and signs,cardiovascular reflex tests based on HR and BP,short-term electrocardiography(ECG),QT interval prolongation,HR variability(24 h,classic24 h Holter ECG),ambulatory BP monitoring,HR turbulence,baroreflex sensitivity,muscle sympathetic nerve activity,catecholamine assessment and cardiovascular sympathetic tests,heart sympathetic imaging.Although it is common complication,the significance of CAN has not been fully appreciated and there are no unified treatment algorithms for today.Treatment is based on early diagnosis,life style changes,optimization of glycemic control and management of cardiovascular risk factors.Pathogenetic treatment of CAN includes:Balanced diet and physical activity;optimization of glycemic control;treatment of DLP;antioxidants,first of allα-lipoic acid(ALA),aldose reductase inhibitors,acetylL-carnitine;vitamins,first of all fat-soluble vitamin B1;correction of vascular endothelial dysfunction;prevention and treatment of thrombosis;in severe cases-treatment of OH.The promising methods include prescription of prostacyclin analogues,thromboxane A2 blockers and drugs that contribute into strengthening and/or normalization of Na^+,K^+-ATPase(phosphodiesterase inhibitor),ALA,dihomo-γ-linolenic acid(DGLA),ω-3 polyunsaturated fatty acids(ω-3 PUFAs),and the simultaneous prescription of ALA,ω-3 PUFAs and DGLA,but the future investigations are needed.Development of OH is associated with severe or advanced CAN and prescription of nonpharmacological and pharmacological,in the foreground midodrine and fludrocortisone acetate,treatment methods are necessary.

Cardiovascular autonomic neuropathy in diabetes:Pathophysiology,clinical assessment and implications

Cardiovascular autonomic neuropathy(CAN)is a debilitating condition that mainly occurs in long-standing type 2 diabetes patients but can manifest earlier,even before diabetes is diagnosed.CAN is a microvascular complication that results from lesions of the sympathetic and parasympathetic nerve fibers,which innervate the heart and blood vessels and promote alterations in cardiovascular autonomic control.The entire mechanism is still not elucidated,but several aspects of the pathophysiology of CAN have already been described,such as the production of advanced glycation end products,reactive oxygen species,nuclear factor kappa B,and pro-inflammatory cytokines.This microvascular complication is an important risk factor for silent myocardial ischemia,chronic kidney disease,myocardial dysfunction,major cardiovascular events,cardiac arrhythmias,and sudden death.It has also been suggested that,compared to other traditional cardiovascular risk factors,CAN progression may have a greater impact on cardiovascular disease development.However,CAN might be subclinical for several years,and a late diagnosis increases the mortality risk.The duration of the transition period from the subclinical to clinical stage remains unknown,but the progression of CAN is associated with a poor prognosis.Several tests can be used for CAN diagnosis,such as heart rate variability(HRV),cardiovascular autonomic reflex tests,and myocardial scintigraphy.Currently,it has already been described that CAN could be detected even during the subclinical stage through a reduction in HRV,which is a non-invasive test with a lower operating cost.Therefore,considering that diabetes mellitus is a global epidemic and that diabetic neuropathy is the most common chronic complication of diabetes,the early identification and treatment of CAN could be a key point to mitigate the morbidity and mortality associated with this long-lasting condition.

Positive effects of music therapist's selected auditory stimulation on the autonomic nervous system of patients with disorder of consciousness: a randomized controlled trial

The current randomized controlled trial was performed at the China Rehabilitation Science Institute, China to test the hypothesis that musical auditory stimulation has positive effects on the autonomic nervous system of patients with disorder of consciousness.Although past studies have recommended that patients with disorder of consciousness listen to patient-preferred music, this practice is not universally accepted by researchers.Twenty patients with severe disorder of consciousness listened to either therapist-selected(n = 10, 6 males and 4 females;43.33 ± 18.76 years old) or patient-preferred(n = 10, 5 males and 5 females, 48.83 ± 18.79 years old) musical therapy, 30 minutes/day, 5 times/week for 6 weeks.The results showed no obvious differences in heart rate variability-related parameters including heart rate, standard deviation of normal-to-normal R-R intervals, and the root-mean-square of successive heartbeat interval differences of successive heartbeat intervals between the two groups of patients.However, percentage of differences exceeding 50 ms between adjacent normal number of intervals, low-frequency power/high-frequency power, high-frequency power norm, low-frequency power norm, and total power were higher in patients receiving therapist-selected music than in patients receiving their own preferred music.In contrast, this relationship was reversed for the high-frequency power and very-low-frequency band.These results suggest that compared with preferred musical stimulation, therapist-selected musical stimulation resulted in higher interactive activity of the autonomic nervous system.Therefore, therapist-selected musical stimulation should be used to arouse the autonomic nervous system of patients with disorder of consciousness.This study was approved by the Institutional Ethics Committee of China Rehabilitation Research Center, China(approval No.2018-022-1) on March 12, 2018 and registered with the Chinese Clinical Trial Registry(registration number Chi CTR1800017809) on August 15, 2018.