Estudio de variabilidad de la frecuencia cardiaca en pacientes con sospecha de fallas autonómicas. Utilización del Holter y el Diagrama de Poincare

El estudio de la regularidad de la Frecuencia Cardiaca, a través del Holter de 24 horas se hace desde la década de los años 60 y es bastante efectivo. Sin embargo, desde los años noventa comenzaron a efectuarse estudios cortos de Holter en pacientes sospechados de tener fallas autonómicas de control de la frecuencia cardiaca, especialmente en pacientes con comorbilidades tales como Hipertensión, Diabetes Mellitus, Aterosclerosis etc. De aquí la importancia de realizar un test de Holter de diez minutos, divididos en dos tiempos de 5 minutos, primero en decúbito dorsal y luego en bipedestación, especialmente en pacientes de más de cincuenta años o con comorbilidades presentes. Los resultados se presentan luego en gráficos de Poincare, que incluye el programa operativo del dispositivo, que permite un vistazo de la elipse con sus dos ejes, que representan las acciones simpáticas y parasimpáticas sobre la frecuencia cardiaca. Una variabilidad anormal de la frecuencia cardiaca debe ser luego estudiada más profundamente a fin de reafirmar el diagnóstico y ulteriores pasos en el tratamiento.

The variability of Cardiac Frequency is a valuable monitor of the autonomic function and is currently used as tool for study of changes of regularity through Holter 24 hours. From nighties, several researchers have been oriented to stablish relationship between VCF and autonomic failure, especially in patients with comorbidities, such as Hypertension, Diabetes Mellitus, atherosclerosis etc. Actually is well known that a lost or VCF or a minor variability, even in short traces of Holter in 10 minutes, means an autonomic failure, of baroreflex and quimioreflex resources. Hence, the importance of performing test of ten minutes Holter, five in decubitus position and five in standing, to patients of more than fifty years old, or less if comorbidities are presents, to design a Poincare diagram, which is special to indicate in quick view the prevalence of Sympathetic o Vagal action on cardiac frequency; that conduces to a more deep study of Autonomic failure, such tilt test, extended holter of 24 hours, and others medicals images resources.

Cutting-edge issues in sympathetic ophthalmia approach and six case reports: a T cell-mediated autoimmune response / As questões de ponta na abordagem da oftalmia simpática e 6 relatos de caso: uma resposta autoimune mediada por células T

ABSTRACT Sympathetic ophthalmia is a rare and potentially devastating bilateral diffuse granulomatous panuveitis. It is caused by surgical or non-surgical eye injuries and is an uncommon and serious complication of trauma. It is diagnosed clinically and supported by imaging examinations such as ocular ultrasonography and optical coherence tomography. Its treatment consists of immunosuppressive therapy with steroids and sometimes steroid-sparing drugs, such as cyclosporine, azathioprine, cyclophosphamide, and mycophenolate mofetil. Fast and effective management with systemic immunosuppressive agents allows for disease control and achievement of good visual acuity in the sympathizing eye. By contrast, enucleation should be considered only in situations where the injured eye has no light perception or in the presence of severe trauma. In addition to a bibliographic review of this topic, we report six cases involving different immunosuppressive and surgical treatment modalities.

RESUMO A oftalmia simpática consiste em uma panuveíte granulomatosa bilateral rara e potencialmente devastadora, ocorrendo geralmente após trauma ocular cirúrgico ou não cirúrgico. O diagnóstico é baseado em aspectos clínicos e apoiado por exames de imagem, como ultrassonografia ocular e tomografia de coerência óptica. O tratamento consiste em terapia imunossupressora com esteróides e, eventualmente, drogas poupadoras de esteróides, como ciclosporina, azatioprina, ciclofosfamida e micofonato de mofetila. O manejo rápido e eficaz com agentes imunossupressores sistêmicos permite o controle da doença e a obtenção de boa acuidade visual no olho simpatizante. A enucleação, por outro lado, poderia ser considerada apenas em situações em que o olho lesado não tem percepção luminosa ou há trauma grave. Além de uma revisão bibliográfica sobre o tema, foi relatada uma série de 6 casos com diferentes modalidades de tratamento imunossupressor e cirúrgico.

Electroacupuncture at Sensitized Acupoints Relieves Somatic Referred Pain in Colitis Rats by Inhibiting Sympathetic-Sensory Coupling to Interfere with 5-HT Signaling Pathway / 中国结合医学杂志

OBJECTIVE@#To investigate whether electroacupuncture (EA) at sensitized acupoints could reduce sympathetic-sensory coupling (SSC) and neurogenic inflammatory response by interfering with 5-hydroxytryptamine (5-HT)ergic neural pathways to relieve colitis and somatic referred pain, and explore the underlying mechanisms.@*METHODS@#Rats were treated with 5% dextran sodium sulfate (DSS) solution for 7 days to establish a colitis model. Twelve rats were randomly divided into the control and model groups according to a random number table (n=6). According to the "Research on Rat Acupoint Atlas", sensitized acupoints and non-sensitized acupoints were determined. Rats were randomly divided into the control, model, Zusanli-EA (ST 36), Dachangshu-EA (BL 25), and Xinshu (BL 15) groups (n=6), as well as the control, model, EA, and EA + GR113808 (a 5-HT inhibitor) groups (n=6). The rats in the control group received no treatment. Acupuncture was administered on 2 days after modeling using the stimulation pavameters: 1 mA, 2 Hz, for 30 min, with sparse and dense waves, for 14 consecutive days. GR113808 was injected into the tail vein at 5 mg/kg before EA for 10 min for 7 consecutive days. Mechanical sensitivity was assessed with von Frey filaments. Body weight and disease activity index (DAI) scores of rats were determined. Hematoxylin and eosin staining was performed to observe colon histopathology. SSC was analyzed by immunofluorescence staining. Immunohistochemical staining was performed to detect 5-HT and substance P (SP) expressions. The calcitonin gene-related peptide (CGRP) in skin tissue and tyrosine hydroxylase (TH) protein levels in DRG were detected by Western blot. The levels of hyaluronic acid (HA), bradykinin (BK), prostaglandin I2 (PGI2) in skin tissue, 5-HT, tryptophan hydroxylase 1 (TPH1), serotonin transporters (SERT), 5-HT 3 receptor (5-HT3R), and 5-HT 4 receptor (5-HT4R) in colon tissue were measured by enzyme-linked immunosorbent assay (ELISA).@*RESULTS@#BL 25 and ST 36 acupoints were determined as sensitized acupoints, and BL 15 acupoint was used as a non-sensitized acupoint. EA at sensitized acupoints improved the DAI score, increased mechanical withdrawal thresholds, and alleviated colonic pathological damage of rats. EA at sensitized acupoints reduced SSC structures and decreased TH and CGRP expression levels (P<0.05). Furthermore, EA at sensitized acupoints reduced BK, PGI2, 5-HT, 5-HT3R and TPH1 levels, and increased HA, 5-HT4R and SERT levels in colitis rats (P<0.05). GR113808 treatment diminished the protective effect of EA at sensitized acupoints in colitis rats (P<0.05).@*CONCLUSION@#EA at sensitized acupoints alleviated DSS-induced somatic referred pain in colitis rats by interfering with 5-HTergic neural pathway, and reducing SSC inflammatory response.

Bilateral electrodermal activity and asymmetric responses in normal healthy individuals

Background: Electrodermal activity (EDA) or galvanic skin response (GSR) is the change in the electrical properties of the skin which is used to measure the sympathetic activity and response. When a painful stimulus is applied, it elicits a sympathetic response by increasing sweat gland activity that, in turn, increases the skin conductance. Central nervous system plays important role in regulating sympathetic activity. Aims and Objectives: The objectives of this study were as follows: (1) To evaluate the electrodermal responses (EDR) in dominant and non-dominant hand; (2) to compare the EDRs in dominant and non-dominant hand. Materials and Methods: The study was done among MBBS students of age 18–23 years in physiology research laboratory and EDA values were analyzed using BIOCHART software (version1.0) through physiograph. EDA was recorded using skin surface electrodes. Pulse and blood pressure were monitored before and after immersion in cold water. Baseline recording, recording after immersion of hand in cold water, and recovery recording of GSR were noted in dominant and non-dominant hands. Results: The mean GSR, baseline value, and the GSR after cold stimulation were significantly more in non-dominant hand compared to dominant hand. Conclusion: Our findings show an increased sympathetic activity in non-dominant hand in response to cold stimulation compared to dominant hand.

A case report of late-onset MELAS with paroxysmal sympathetic hyperactivity syndrome / 中华神经科杂志

Paroxysmal sympathetic hyperactivity (PSH) is a syndrome characterized by paroxysmal tachycardia, increased blood pressure, tachypnea, hyperthermia, profuse sweating, abnormal posture or dystonia. It occurs in diseases such as moderate to severe brain injury, cerebral hypoxia, hydrocephalus, brain tumor and encephalitis. At present, the etiology and pathogenesis are still unclear, and it is easy to be misdiagnosed as epilepsy clinically. This article reports a 43-year-old male patient with late-onset mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) confirmed by genetic testing. During hospitalization, he suddenly developed episodic involuntary limb movements, profuse sweating, tachycardia, and arterial hypertension. He was initially diagnosed with symptomatic epilepsy, but long-term electroencephalogram monitoring showed no synchronized discharge, and he was given antiepileptic drugs. The treatment was also ineffective. Brain magnetic resonance imaging revealed a new lesion in the left insular and insular operculum. Dexmedetomidine, baclofen, and gabapentin were given to suppress sympathetic nerve excitability. Drugs were effective, so the diagnosis was corrected to PSH. There is no report of MELAS complicated with PSH in the previous literature. It is speculated that it may be related to the low clinical cognition of PSH. In this case, new lesions in the insula and insular operculum appeared during the onset of PSH, suggesting that may be related to the pathogenesis of PSH.

Study on preventive and therapeutic effect of Tongbu-fangchan prescription on Ach-CaCl / 中国药理学通报

Aim To explore he preventive and therapeutic effects of Tongbu-fangchan prescription on aceylcholine-calcium chloride (Ach-CaCl

Peripheral BDNF Regulates Somatosensory-Sympathetic Coupling in Brachial Plexus Avulsion-Induced Neuropathic Pain / 神经科学通报·英文版

Brachial plexus avulsion (BPA) is a combined injury involving the central and peripheral nervous systems. Patients with BPA often experience severe neuropathic pain (NP) in the affected limb. NP is insensitive to the existing treatments, which makes it a challenge to researchers and clinicians. Accumulated evidence shows that a BPA-induced pain state is often accompanied by sympathetic nervous dysfunction, which suggests that the excitation state of the sympathetic nervous system is correlated with the existence of NP. However, the mechanism of how somatosensory neural crosstalk with the sympathetic nerve at the peripheral level remains unclear. In this study, through using a novel BPA C7 root avulsion mouse model, we found that the expression of BDNF and its receptor TrκB in the DRGs of the BPA mice increased, and the markers of sympathetic nervous system activity including α1 and α2 adrenergic receptors (α1-AR and α2-AR) also increased after BPA. The phenomenon of superexcitation of the sympathetic nervous system, including hypothermia and edema of the affected extremity, was also observed in BPA mice by using CatWalk gait analysis, an infrared thermometer, and an edema evaluation. Genetic knockdown of BDNF in DRGs not only reversed the mechanical allodynia but also alleviated the hypothermia and edema of the affected extremity in BPA mice. Further, intraperitoneal injection of adrenergic receptor inhibitors decreased neuronal excitability in patch clamp recording and reversed the mechanical allodynia of BPA mice. In another branch experiment, we also found the elevated expression of BDNF, TrκB, TH, α1-AR, and α2-AR in DRG tissues from BPA patients compared with normal human DRGs through western blot and immunohistochemistry. Our results revealed that peripheral BDNF is a key molecule in the regulation of somatosensory-sympathetic coupling in BPA-induced NP. This study also opens a novel analgesic target (BDNF) in the treatment of this pain with fewer complications, which has great potential for clinical transformation.

The Antinociceptive Effect of Sympathetic Block is Mediated by Transforming Growth Factor β in a Mouse Model of Radiculopathy / 神经科学通报·英文版

Although sympathetic blockade is clinically used to treat pain, the underlying mechanisms remain unclear. We developed a localized microsympathectomy (mSYMPX), by cutting the grey rami entering the spinal nerves near the rodent lumbar dorsal root ganglia (DRG). In a chemotherapy-induced peripheral neuropathy model, mSYMPX attenuated pain behaviors via DRG macrophages and the anti-inflammatory actions of transforming growth factor-β (TGF-β) and its receptor TGF-βR1. Here, we examined the role of TGF-β in sympathetic-mediated radiculopathy produced by local inflammation of the DRG (LID). Mice showed mechanical hypersensitivity and transcriptional and protein upregulation of TGF-β1 and TGF-βR1 three days after LID. Microsympathectomy prevented mechanical hypersensitivity and further upregulated Tgfb1 and Tgfbr1. Intrathecal delivery of TGF-β1 rapidly relieved the LID-induced mechanical hypersensitivity, and TGF-βR1 antagonists rapidly unmasked the mechanical hypersensitivity after LID+mSYMPX. In situ hybridization showed that Tgfb1 was largely expressed in DRG macrophages, and Tgfbr1 in neurons. We suggest that TGF-β signaling is a general underlying mechanism of local sympathetic blockade.

Research progress on corneal nerves and substance P in viral keratitis / 国际眼科杂志(Guoji Yanke Zazhi)

Diseases like viral keratitis can harm corneal nerves, which are necessary for maintaining the health and functionality of the cornea. Recent research has shown that corneal nerve pathology affects the infected eye as well as the contralateral one, and that aberrant changes in sympathetic nerves can be seen, with the exception of sensory nerves that correspond to corneal sensation. However, apart from in vivo confocal microscopy and corneal sensation, there have been no additional prognostic indicators that allow clinicians to assess the severity of corneal nerve damage. While multiple functions of corneal nerves are mediated by neuropeptides, substance P, the first topical neuropeptide used in ocular clinical practice, was proved to regulate the process of viral infections, and it is involved in bilateral corneal pathologies through pro-inflammatory and neurotrophic functions in viral keratitis, so it may be used as a diagnostic biomarker or a therapeutic target. Therefore, this review summarized the changes and roles of corneal nerves as well as substance P in viral keratitis, which may serve as a reference for further study into associated mechanisms and clinical applications.

Regulation of Neuro-Microenvironment on Mitochondrial Mass of Hematopoietic Stem and Progenitor Cells / 中国实验血液学杂志

OBJECTIVE@#To study the effects of the neuro-microenvironment on the mass of mitochondria in hematopoietic stem and progenitor cells (HSPC), and to understand the potential mechanisms how nerve regulates HSPC.@*METHODS@#6-hydroxydopamine (6-OHDA) and capsaicin were used to interfere with the function of sympathetic nerve and nociceptive nerve in mitochondria-GFP reporter mice, respectively. The fluorescence intensity of GFP in bone marrow and spleen was measured by flow cytometry. The GFP median fluorescence intensity (MFI) of HSPC in normal bone marrow and spleen was analyzed and compared. The changes of the mitochondrial mass in HSPCs in each group after denervation were compared.@*RESULTS@#Hematopoietic stem cells (HSC) had the highest mito-GFP MFI in steady-state (49 793±1 877), and the mito-GFP MFI gradually decreased during the differentiation of HSCs. Compared with control group, pharmaceutical nociceptive denervation significantly increased the mito-GFP MFI of bone marrow multipotent progenitor-1 (MPP1, 50 751±420 vs 44 020±510) and LKS- cells (15 673±65 vs 13 979±103); pharmaceutical sympathetic denervation significantly reduced the mito-GFP MFI of bone marrow LKS+ cells (21 667±351 vs 29 249±973).@*CONCLUSION@#Sympathetic and nociceptive nerves can regulate the mass of mitochondria in HSPC and affect the function of HSPCs.

Clinical research progress and mechanism on myocardial injury in hearts from donors with stroke / 器官移植

At present, the heart of donor from donation after brain death are the primary organ sources for heart transplantation. After brain death, severe hemodynamic changes and a series of organ functional changes will occur, thereby leading to the functional damage or even loss of tissues and organs, especially the heart. Intimate relationship and interaction have been found in the physiology and pathophysiology between nervous and cardiovascular systems. After stroke, autonomic nervous disorder, neuroendocrine disorder and intense and persistent inflammatory reaction could be caused by the brain-heart axis reaction, leading to stroke-induced cardiac injuries, such as sympathetic storm, catecholamine storm, inflammatory storm, etc. In this article, research progresses on the mechanism of myocardial injury in heart from donors with stroke and the effect on clinical efficacy and prognosis after heart transplantation were reviewed, aiming to provide reference for clinical practice and subsequent research.

Dysautonomia Evaluation by Holter in Chagas Heart Disease

Abstract Background Sudden cardiac death is the main lethal mechanism associated with Chagas cardiomyopathy. Studies suggest that dysautonomia may represent a relevant, intense, independent, and early phenomenon in the natural history of the disease, even when ventricular systolic function is preserved, and may also be the mechanism that triggers malignant ventricular arrhythmias. Objective To evaluate the degree of dysautonomia and its possible association with ventricular arrhythmias in patients with Chagas cardiomyopathy, according to different categories of mortality risk, as defined by the score proposed by Rassi, used as a surrogate outcome for death. Methods A cross-sectional study involving 43 patients with Chagas cardiomyopathy stratified into risk categories based on the Rassi score, with 23 being classified as low risk and 20 as intermediate-to-high risk. Heart rate variability (HRV) was assessed using Holter monitoring for long-term recordings of 24 hours (time domain) and for short-term recordings of 5 minutes (frequency domain) at rest and after autonomic tests: deep breathing and Valsalva maneuver. The HRV variables were compared between the groups using the Student's t-test and α=0.05. Results Comparison of the results between the risk stratification groups showed no differences in HRV indexes, either in the time or frequency domain. However, results showed a significant increase in the number of arrhythmias as a function of increased risk (p=0.02). Conclusion There was no association between the degree of dysautonomia, evaluated by Holter monitoring, and the categories of mortality risk, despite a direct association between the rate of arrhythmias and the higher risk group.

No obvious symptoms in acute (eltroxin) thyroxine poisoning in euthyroid – A case report

Levothyroxine (T4) (Eltroxin) poisoning is a rare clinical entity which is usually asymptomatic. It can occur accidently, mostly in children, and can happen intentionally in adults with suicidal intention especially psychiatric patients. Thyrotoxicosis from an overdose of medicinal thyroid hormone is a condition that may be associated with a significant delay in onset of toxicity. However, severe symptoms such as respiratory failure, malignant hyperthermia, seizures, arrhythmia, and coma have been reported. In this case report, we present a patient who ingested high doses of levothyroxine i.e., 90 tab. of Eltroxin 100 mcg, for suicidal intension and admitted to intensive care unit. She is an euthyroid person but took these tablets, which her mother was taking Eltroxin tablets for hypothyroidism. Gastric lavage was done with activated charcoal, Inj. Hydrocortisone, Tab Propranolol and Tab Neomercazole administered. Despite ingestion of high dose of levothyroxine, thyrotoxicosis symptoms like palpitations resolved with appropriate treatment and the patient was discharged after complete recovery.

Effect of endurance training on sympathetic reactivity by sustained hand grip test

Background: The endurance training plays a key role in maintaining not only the physical fitness but also overall wellness of an individual. It boosts up the immune system and cardiovascular endurance. The training responses were found to be better in hypertensive patients as compared to normotensives. Aims and Objectives: The aims of this study were to evaluate the effect of endurance training on blood pressure (BP) response to sustained hand grip in the study group and control group before and after 3 months of training. Materials and Methods: Sixty apparently healthy young subjects divided into two groups: Exercise group (30 subjects) control group (30 subjects). Exercise group performed endurance training by running on treadmill alternately for 3 months, while control group did nothing. Tests were carried out with the help of CANWin machine which uses Tacho Cardio Gramme response to sustained hand grip for assessment of sympathetic function reactivity. For the test, subjects were asked to maintain the pressure on dynamometer for 5 min at 30% of maximum voluntary contraction. The BP was recorded at first before start of isometric contraction and at 5 min after the onset of isometric contraction. Results: No statistically significant difference was found in the mean systolic BP (SBP) and mean diastolic BP (DBP) between the exercise and the control group before exercise and after 5 min during exercise. Statistically significant difference was found in the mean change in DBP, but no significant mean change in SBP was found between exercise and control group before exercise and 5 min after (during exercise) after completing endurance training. A significant difference was observed among the exercise group in the change in SBP at 5 min after hand grip during exercise. Conclusion: Parasympathetic functions show favorable changes with aerobic exercise, while sympathetic system does not show such responses.

Comparison of the autonomic nervous system dysfunction between different chronic spine disorders: neck pain versus low back pain

SUMMARY OBJECTIVE: This study aims to compare heart rate variability (HRV) between patients with chronic neck pain and patients with chronic low back pain and to correlate the chronic pain variables with heart rate variability indices. METHODS: This is a cross-sectional study. We divided the sample into two groups: neck pain (n=30) and low back pain (n=30). We used the Numeric Pain Rating Scale, Neck Disability Index, Roland-Morris Disability Questionnaire, Pain-Related Catastrophizing Thoughts Scale, Tampa Scale of Kinesiophobia, and Pain Self-Efficacy Questionnaire. For heart rate variability analysis, we used the following indices: mean RR, standard deviation of all RR intervals, mean heart rate, root mean square differences of successive RR intervals, triangular index, triangular interpolation of the interval histogram, low-frequency band in arbitrary units and in absolute values, high-frequency band in arbitrary units and in absolute values, standard deviation of the instantaneous beat-to-beat variability (standard deviation 1), long-term standard deviation of continuous RR intervals (standard deviation 2), and Stress Index. We used Student's t-test for comparisons and Spearman's coefficient for correlations. RESULTS: We observe insignificant values in the differences between the groups. Disability and self-efficacy were correlated with heart rate variability only in patients with chronic neck pain, whereas catastrophizing and kinesiophobia showed greater correlations with heart rate variability in patients with chronic low back pain. CONCLUSIONS: Autonomic dysfunction of individuals with chronic neck pain, when compared to patients with chronic low back pain, does present insignificant differences.

Meta-Analysis of Pulmonary Artery Denervation for Treatment of Pulmonary Hypertension

ABSTRACT Introduction: Pulmonary artery denervation (PADN) can reduce the sympathetic nervous system (SNS) activity, reduce pulmonary artery pressure (PAP), and improve the quality of life in patients with pulmonary hypertension (PH). We conducted a systematic meta-analysis of the effectiveness of PADN in the treatment of PH patients. Methods: This is a comprehensive literature search including all public clinical trials investigating the effects of PADN on PH. Outcomes were mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), cardiac output (CO), right ventricular (RV) Tei index, 6-minute walk distance (6MWD), and New York Heart Association (NYHA) cardiac function grading. Results: A total of eight clinical studies with 213 PH patients who underwent PADN were included. Meta-analysis showed that after PADN, mPAP (mean difference [MD] -12.51, 95% confidence interval [CI] -17.74 to -7.27, P<0.00001) (mmHg) and PVR (MD -5.17, 95% CI -7.70 to -2.65, P<0.0001) (Wood unit) decreased significantly, CO (MD 0.59, 95% CI 0.32 to 0.86, P<0.0001) (L/min) and 6MWD (MD 107.75, 95% CI 65.64 to 149.86, P<0.00001) (meter) increased significantly, and RV Tei index (MD -0.05, 95% CI -0.28 to 0.17, P=0.63) did not change significantly. Also after PADN, the proportion of NYHA cardiac function grading (risk ratio 0.23, 95% CI 0.14 to 0.37, P<0.00001) III and IV decreased significantly. Conclusion: This meta-analysis supports PADN as a potential new treatment for PH. Further high-quality randomized controlled studies are needed.

Efeitos da corrente interferencial no sistema nervoso autônomo em voluntários saudáveis: ensaio clínico randomizado / Effects of interferential current on autonomic nervous system in healthy volunteers: randomized clinical trial

Avaliar os efeitos de diferentes frequências moduladas em amplitude (AMF-100Hz e AMF-10Hz) da corrente interferencial (CI) sobre o sistema nervoso autônomo (SNA) de voluntários saudáveis. Trinta voluntários saudáveis (23,7±2,7 anos) foram randomizados em intervenções placebo (desligado), CI com AMF-100Hz e CI com AMF-10Hz. As intervenções foram aplicadas na região ganglionar paravertebral por 30 minutos. O SNA foi avaliado pela variabilidade da frequência cardíaca antes e imediatamente após as intervenções. A intervenção em 10Hz reduziu a atividade simpática em 6% e aumentou a parassimpática em 6%. A intervenção de 100Hz aumentou 12% para a atividade simpática e diminuiu 12% para a atividade parassimpática. A CI altera o equilíbrio autonômico em voluntários saudáveis. 10Hz reduz a atividade simpática e aumenta parassimpático, embora o 100Hz tenha resultados opostos. A CI a 10Hz melhora o equilíbrio autonômico e apresenta efeitos potenciais a serem testados em pacientes hipertensos.

To evaluate the effects of different amplitude-modulated frequency (AMF-100Hz and AMF-10Hz) of the interferential current (IC) on autonomic nervous system (ANS) in healthy volunteers. Thirty healthy volunteers (23.7 ±2.7 years old) were randomized into placebo interventions (turned off), IC with AMF-100Hz and IC with AMF-10Hz. Interventions ware applied in the paravertebral ganglionar region for 30 minutes. ANS evaluated by the heart rate variability before and immediately after the interventions. 10Hz intervention reduced the sympathetic activity in 6% and an increase in the parasympathetic in 6%. 100Hz intervention increased 12% to sympathetic activity and decreased 12% to parasympathetic activity. IC changes the autonomic balance in healthy volunteers. 10Hz reduces the sympathetic activity and increases parasympathetic, although the 100Hz has opposite results. The IC at 10Hz improves the autonomic balance and presents potential effects to be tested in hypertensive patients.

Nationwide surveillance for S-Metoprololtreatment effect on blood pressure control against sympathetic overdrive in Indian patients with hypertension (PROTECT)

Background:Patients with hypertension in India been reported with high heart rate owing to sympathetic overdrive (SO). Beta-blockers provides several positive effects to reduce SO in patients with hypertension. The aim of present survey studywasto understand current real-world prevalence of SO in Indian patients with hypertension and usage of beta-blocker therapy in them.Methods:A cross sectional, observational, questionnaire-based survey conducted across India between June 2020 to October 2020. A specially designed validated questionnaire was shared with 157 registered health care practitioners (HCP),their anonymous inputs were captured and analysed in qualitative manner. Categorical data was summarized by number (n) and percentage (%). Results:Total 157 HCP participated and completed the survey. Around 53% of HCP observed that patients with average heart rate above 75 beats/min were associated with negative prognosis. Around 43% of HCP reported that raised heart rate is associated with advancedage and increased body mass index (BMI). Two-third of HCP reported that tachycardia is associated with stage-2 hypertension and marked by restlessness and anxiety which is suggestive of SO. Over 70% HCP agreed that the HR below 75 beats/min is associated with good prognosis. Around 89% HCP reported beta-blockers as the drug of choice in patients with augmented SO. S-Metoprololwas reported to bethemost preferred beta-blocker agent and was recommended by 76% HCP in patients with hypertension and coexisting SO.Conclusions:SO been reported prevalent conditionin Indian patients with hypertension which likely worsensthe prognosis in these patients. Beta-blockers reported to be the preferred choice of anti-hypertensive and S-Metoprololseem to be themost preferred agent amongst the available beta-blockers against SO in patients with hypertension in India.

Patterns of renal and splanchnic sympathetic vasomotor activity in an animal model of survival to experimental sepsis

Sepsis causes long-term disability, such as immune dysfunction, neuropsychological disorders, persistent inflammation, catabolism, and immunosuppression, leading to a high risk of death in survivors, although the contributing factors of mortality are unknown. The purpose of this experimental study in rats was to examine renal (rSNA) and splanchnic (sSNA) sympathetic nerve activity, as well as baroreflex sensitivity, in acute and chronic post-sepsis periods. The rats were divided into two groups: control group with naïve Wistar rats and sepsis group with 2-mL intravenous inoculation of Escherichia coli at 108 CFU/mL. Basal mean arterial pressure, heart rate, rSNA, sSNA, and baroreflex sensitivity were evaluated in all groups at the acute (6 h) and chronic periods (1 and 3 months). Basal rSNA and sSNA were significantly reduced in the surviving rats, as was their baroreflex sensitivity, for both pressor and hypotensive responses, and this effect lasted for up to 3 months. A single episode of sepsis in rats was enough to induce long-term alterations in renal and splanchnic sympathetic vasomotor nerve activity, representing a possible systemic event that needs to be elucidated. These findings showed that post-sepsis impairment of sympathetic vasomotor response may be one of the critical components in the inability of sepsis survivors to respond effectively to new etiological illness factors, thereby increasing their risk of post-sepsis morbidity.

Estratificação de Risco e Avaliação da Atividade Simpática Cardíaca Utilizando Imagem Miocárdica com [123I] MIBG na Denervação Renal / Risk Stratification and Cardiac Sympathetic Activity Assessment Using Myocardial [123I] MIBG Imaging in Renal Denervation

Resumo A hiperativação do sistema nervoso simpático desempenha um papel central na fisiopatologia da hipertensão. O objetivo deste estudo foi avaliar a atividade simpática cardíaca e investigar o papel da cintigrafia miocárdica com metaiodobenzilguanidina com 123I ([123I] MIBG) na estratificação de risco cardiovascular de pacientes com hipertensão resistente tratados com denervação renal (DR). Dezoito pacientes foram incluídos neste estudo prospectivo (média de idade de 56 ± 10 anos, 27,8% mulheres). Ecocardiograma transtorácico, análise geral do sangue e cintilografia miocárdica com [(123I) MIBG] foram realizados antes e seis meses após a DR. Um paciente era considerado respondedor (R) se uma diminuição ≥ 5 mmHg na pressão arterial sistólica (PAS) média ambulatorial fosse observada no seguimento de seis meses. 66,7% dos pacientes foram R (diminuição na PAS de 20,6 ± 14,5 mmHg, vs. menos 8 ± 11,6 mmHg em não-respondedores (NR), p = 0,001). A relação coração-mediastino (RCM) inicial foi significativamente menor na linha basal no grupo R (1,6 ± 0,1 vs. 1,72 ± 0,1, p <0,02), mas semelhante em seis meses. Considerando os dois momentos no tempo, o grupo R teve valores iniciais de RCM mais baixos do que o grupo NR (p <0,05). Tanto o RCM tardio quanto a taxa de washout foram idênticos e nenhuma correlação significativa entre a resposta à DR ou qualquer índice de imagem com MIBG foi encontrada. A denervação renal efetivamente reduziu a pressão arterial na maioria dos pacientes, mas a imagem com [123I] MIBG não foi útil na previsão da resposta. Entretanto, houve evidência de overdrive do sistema nervoso simpático e, tanto a RCM inicial quanto tardia estavam reduzidas em geral, provavelmente colocando essa população em um risco maior de eventos adversos.

Abstract Hyperactivation of the sympathetic nervous system plays a central role in the pathophysiology of hypertension. The aim of this study was to assess cardiac sympathetic activity and investigate the role of myocardial123I-labelled meta-iodo benzyl guanidine ([123I] MIBG) scintigraphy in cardiovascular risk stratification of patients with resistant hypertension treated with renal denervation (RDN). Eighteen patients were included in this prospective study (mean age 56 ± 10 years old, 27.8% females). Transthoracic echocardiogram, general blood analysis and myocardial ([123I] MIBG scintigraphy were performed before and six-months after RDN. A patient was considered a responder (R) if a drop ≥ 5mmHg on mean systolic ambulatory blood pressure (BP) monitoring was observed at the six-month follow-up. 66.7% of patients were R (drop in systolic BP of 20.6 ± 14.5mmHg, vs minus 8 ± 11.6mmHg in non-responders (NR), p=0.001). Early heart-mediastinum ratio (HMR) was significantly lower at baseline in the R group (1.6 ± 0.1 vs 1.72 ± 0.1, p<0.02) but similar at six months. Considering both instants in time, the R group had lower early HMR values than the NR group (p<0.05). Both the late HMR and the washout rate were identical and no significant correlation between response to RDN or any MIBG imaging index was found. Renal denervation effectively lowered blood pressure in the majority of patients but [123I] MIBG was not useful in predicting the response. However, there was evidence of sympathetic overdrive and, both early and late HMR were overall reduced, probably putting this population at a higher risk of adverse events.