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Abstract: Introduction: The variables determinants of physical performance in cross-country marathon of mountain biking (XCMMTB) are still unknown. Objective: We aimed to verify the training control variables and the physiological responses in an official XCM-MTB race. Material and methods: 13 athletes (11 men and 2 women; 33.3 ± 12.7 years of age) participated in this study. It was conducted during an official XCM-MTB in Brazil (route of 70 km). The heart rate (HR), altimetry, velocity, temperature, pacing, and power were obtained every 10 km travelled by the STRAVA application. Multiple linear regression analysis was performed to verify whether the variables could predict physical performance. Results: The athletes maintained constant HR elevation in the corresponding zone 80% HRmax. They also presented a variation in the pacing (F = 35.82; p < 0.001; d = 0.66) and power (F = 7.20; p < 0.001; d = 0.18) showing higher values in the last 10 km. Only pacing can be considered a predictor of the physical performance (β = 0.958; t = 7.30; p < 0.001), specifically the one at 20 km (F = 10.23; p = 0.004; R2 = 0.82). Conclusion: The study concluded that the analyzed variables are reliable for the performance control in an official XCMMTB race. HR and power are variables that can be used to prescribe and control training, as they change according to the requirements of the race. Power can also be used as a performance predictor as it is directly influenced by terrain.
Resumen: Introducción: Las variables determinantes del rendimiento físico en una maratón de ciclismo de montaña (XCM-MTB) aún son desconocidas. Objetivo: Nuestro objetivo fue verificar las variables fisiológicas y de control del entrenamiento en una carrera oficial de XCM-MTB. Materiales y métodos: 13 atletas (11 hombres y 2 mujeres; 33,3 ± 12,7 años) participaron en este estudio. La investigación se realizó durante un XCM-MTB oficial en Brasil (recorrido de 70 km). La frecuencia cardíaca (FC), la altimetría, la velocidad, la temperatura, el ritmo y la potencia se obtuvieron cada 10 km recorridos por la aplicación STRAVA. Se realizó un análisis múltiple de regresión linear para verificar si las variables podían predecir el rendimiento físico. Resultados: Hubo una elevación constante de la FC correspondiente al 80 % de la FCmax. El ritmo presentó una variación (F = 35,82; p < 0,001; d = 0,66) y potencia (F = 7,20; p < 0,001; d = 0,18) con valores superiores en los últimos 10 km. Solo el ritmo a los 20 km (F = 10,23; p = 0,004; R2 = 0,82) puede considerarse predictor del rendimiento físico (β = 0,958; t = 7,30; p < 0,001). Conclusión: El estudio concluyó que las variables analizadas son fiables para la prescripción y control del entrenamiento en una carrera oficial de XCM-MTB. La FC y la potencia son variables que se pueden utilizar para prescribir el entrenamiento. La potencia también se puede utilizar para predecir el rendimiento, ya que está directamente influenciada por el terreno.
Resumo: Introdução: As variáveis determinantes do desempenho físico na maratona de mountain bike cross-country (XCMMTB) ainda são desconhecidas. Objetivo: Nosso objetivo foi verificar as variáveis de controle de treinamento e as respostas fisiológicas em uma corrida oficial de XCMMTB. Material e métodos: Participaram deste estudo 13 atletas (11 homens e 2 mulheres; 33,3 ± 12,7 anos de idade). O estudo foi realizado durante uma corrida oficial de XCM-MTB no Brasil (percurso de 70 km). A frequência cardíaca (FC), altimetria, velocidade, temperatura, ritmo e potência foram obtidos a cada 10 km percorridos através do aplicativo STRAVA. Foi realizada uma análise de regressão linear múltipla para verificar se as variáveis poderiam prever o desempenho físico. Resultados: Os atletas mantiveram uma elevação constante na FC na zona correspondente a 80% da FC máxima. Apresentaram também variação no ritmo (F = 35,82; p < 0,001; d = 0,66) e na potência (F = 7,20; p < 0,001; d = 0,18), mostrando valores mais altos nos últimos 10 km. Apenas o ritmo pode ser considerado um preditor do desempenho físico (β = 0,958; t = 7,30; p < 0,001), especificamente no ponto dos 20 km (F = 10,23; p = 0,004; R2 = 0,82). Conclusão: O estudo concluiu que as variáveis analisadas são confiáveis para o controle de desempenho em uma corrida oficial de XCMMTB. A FC e a potência são variáveis que podem ser usadas para prescrever e controlar o treinamento, pois mudam de acordo com as exigências da corrida. A potência também pode ser usada como um preditor de desempenho, pois é diretamente influenciada pelo terreno.
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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.
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ObjectiveTo explore the impact of autonomic nerve function on motor function in patients with post-stroke depression (PSD) from the perspective of regional homogeneity (ReHo). MethodsFrom January to December, 2020, a total of 60 inpatients and outpatients with cerebral infarction in the Affiliated Brain Hospital of Nanjing Medical University were divided into control group (n = 30) and PSD group (n = 30). Two groups were assessed using Fugl-Meyer Assessment (FMA), modified Barthel Index (MBI) and Hamilton Depression Scale (HAMD). Heart rate variability (HRV) was measured. Ten patients in each group were selected randomly to undergo resting state functional magnetic resonance imaging (rs-fMRI) to calculate ReHo. ResultsAll HRV indices were lower in PSD group than in the control group (|t| > 2.092, P < 0.05). In PSD group, FMA and MBI scores showed positive correlations with 24-hour standard deviation of normal-to-normal R-R intervals (SDNN), the root mean square of successive differences between normal heartbeats over 24 hours (RMSSD), the percentage of differences between adjacent normal R-R intervals over 24 hours that were greater than 50 ms (PNN50), total power (TP), very low frequency power (VLF) and low frequency power (LF) (r > 0.394, P < 0.05), and showed negative correlations with HAMD scores (|r| > 0.919, P < 0.001). HAMD scores in PSD group were negatively correlated with SDNN, RMSSD, PNN50, TP and VLF (|r| > 0.769, P < 0.001). Compared with the control group, the ReHo increased in PSD group in the right rectus gyrus (142 voxels, t = 6.575), the left medial and paracingulate gyri (204 voxels, t = 4.925) (GRF correction, P-Voxel < 0.005，P-Cluster < 0.05); and reduced in the right cerebellum (191 voxels, t = -6.487), the left middle temporal gyrus (140 voxels, t = -5.516), and the left precentral gyrus (119 voxels, t = -4.764) (GRF correction, P-Voxel < 0.005，P-Cluster < 0.05) in PSD group. ConclusionAutonomic nerve function is related to motor dysfunction in patients with PSD. The modulation of emotional, cognitive and motor brain regions by the autonomic nervous system may play a role in influencing the motor function in patients with PSD.
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@#Objective To explore the predictive value of systolic pulmonary artery pressure (SPAP) on autonomic nerve excitation in patients with valvular disease, so as to provide reference for the formulation of clinical intervention plans. Methods The clinical data of patients with valvular disease who received surgical treatment in the General Hospital of Northern Theater Command from August 28, 2020 to February 3, 2021 were prospectively collected. According to the standard deviation of normal-to-normal R-R intervals (SDNN) of the heart rate variability (HRV) of the long-range dynamic electrocardiogram (ECG) 7 days before the operation, the patients were divided into three groups: a sympathetic dominant (SE) group (SDNN≤50 ms), a balance group (50 ms<SDNN<100 ms) and a parasympathetic dominant (PSE) group (SDNN≥100 ms). The correlation between the changes of echocardiographic indexes and autonomic nerve excitation among the groups and the predictive values were analyzed. Results A total of 186 patients were enrolled, including 108 males and 78 females aged 55.92±11.99 years. There were 26 patients in the SE group, 104 patients in the balance group, and 56 patients in the PSE group. The left anteroposterior diameter (LAD), left ventricular end diastolic inner diameter, ratio of peak E to peak A of mitral valve (Em/Am), left ventricular end diastolic volume, left ventricular end systolic volume and SPAP in the SE group were higher than those in the balance group (P<0.05), while peak A of tricuspid valve (At) and left ventricular ejection fraction (LVEF) were lower than those in the balance group (P<0.05). The LAD and Em/Am in the balance group were significantly higher than those in the PSE group (P<0.05). Multivariate analysis showed that patients in the SE group had lower At (right atrial systolic function declines), lower LVEF and higher SPAP than those in the balance group (P=0.04, 0.04 and 0.00). When HRV increased and parasympathetic nerve was excited in patients with valvular disease, Em/Am decreased (left atrial function and/or left ventricular diastolic function declined) with a normal LAD. Pearson analysis showed that there was a linear negative correlation between SPAP and SDNN, with a coefficient of −0.348, indicating that the higher SPAP, the lower HRV and the more excited sympathetic nerve. Receiver operating characteristic curve showed that when SPAP≥45.50 mm Hg (1 mm Hg=0.133 kPa), the sensitivity and specificity of sympathetic excitation in patients with valvular disease were 84.60% and 63.70%, respectively. Conclusion Parasympathetic excitation is an early manifestation of the disease, often accompanied by decreased left atrial function and/or left ventricular diastolic function. Sympathetic nerve excitation can be accompanied by the increase of SPAP and the decrease of left ventricular and right atrial systolic function. SPAP has a unique predictive value for the prediction of autonomic nerve excitation in patients with valvular disease.
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ABSTRACT Objective: To evaluate the relationship between birth weight and the autonomic nervous system in adulthood through a systematic review. Data source: This is a systematic review of publications without limitation of year and language. We included studies involving the autonomic nervous system and birth weight in adults. Manuscripts were selected based on electronic searches of Medical Literature Analysis and Retrieval System Online (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science Cochrane Library and Scopus databases, using "Autonomic Nervous System" OR "Heart Rate" OR "Heart Rate Variability" AND "Birth Weight" as a search strategy. This review is registered on the International Prospective Register of Systematic Reviews — PROSPERO (ID: CRD42020165622). Data synthesis: We found 894 articles; 215 were excluded for duplicity. Of the remaining 679 studies, 11 remained. Two were excluded because they did not specifically treat the autonomic nervous system or birth weight. There were nine publications, two cohort and seven cross-sectional studies. The main findings were that extreme, very low, low or high birth weight may have some impact on the autonomic nervous system in adult life. Conclusions: Birth weight outside the normality rate may have a negative influence on the autonomic nervous system, causing autonomic dysfunction and increasing the risk of cardiovascular diseases in adult life. Thus, the importance of the follow-up of health professionals from pregnancy to gestation and throughout life, with preventive care being emphasized.
RESUMO Objetivo: Avaliar a relação entre o peso ao nascer e o sistema nervoso autônomo na vida adulta por meio de uma revisão sistemática. Fontes de dados: Esta é uma revisão sistemática de publicações, sem limitação de ano e idioma. Incluímos estudos envolvendo o sistema nervoso autônomo e peso ao nascer em adultos. Os manuscritos foram selecionados das bases de dados eletrônicos Medical Literature Analysis and Retrieval System Online (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science Cochrane Library e Scopus, utilizando "Autonomic Nervous System" OR "Heart Rate" OR "Heart Rate Variability" AND "Birth Weight" como estratégia de busca. Esta revisão está registrada pelo International Prospective Register of Systematic Reviews — PROSPERO (ID: CRD42020165622). Síntese dos dados: Nós encontramos 894 artigos. Deles, 215 foram excluídos por duplicidade. Entre os 679 remanescentes, 11 permaneceram, dos quais dois foram excluídos por não tratarem especificamente do sistema nervoso autônomo ou do peso ao nascer. Restaram nove publicações, sendo duas longitudinais e sete transversais. Os principais achados foram que o peso extremo baixo, muito baixo, baixo ou alto ao nascer pode ter algum impacto no sistema nervoso autônomo na vida adulta. Conclusões: O peso ao nascer fora da normalidade pode influenciar negativamente o sistema nervoso autônomo, causando disfunção autonômica e aumentando o risco de doenças cardiovasculares na vida adulta. Assim, ressalta-se a importância do acompanhamento dos profissionais de saúde desde a gravidez até a gestação, pré-natal e ao longo da vida, com cuidados preventivos para esta situação.
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Abstract Objective Evaluate autonomic function and low-grade inflammation and characterize the correlation between these variables in schoolchildren with obesity living in the Brazilian northeast region. Methods 84 children with obesity and 41 with normal weight were included in this cross-sectional study. Anthropometry, body composition, blood pressure (BP), inflammatory biomarkers, and heart rate variability (HRV) indexes were analyzed in children aged 7 to 11 years. Results children with obesity had increased systolic (p= 0.0017) and diastolic (p= 0.0131) BP and heart rate (p= 0.0022). The children with obesity displayed significantly lower SDNN, RMSSD, NN50, HF (ms), HF (nu), SD1, SD2, and higher LF (ms), LF (nu), LF/HF, SD1/SD2, DFA-α1, and DFA-α2, compared to normal weight. A lower and higher capacity for producing IL-10 (p= 0.039) and IL-2 (p= 0.009), respectively, were found in children with obesity compared to children with normal weight. Although IL-2, IL-4 and IL17A did not correlate with HRV parameters, IL-6 was positively correlated with SDNN, LF (ms) and SD2, TNF-α was positively correlated with LF/HF and SD1/SD2 ratio, and IFN-γ was positively correlated with SDNN, RMMSSD, NN50, LF (ms), HF (ms), SD1, and SD2. Conclusions The findings suggest that children with obesity have impaired autonomic function and systemic low-grade inflammation compared to children within the normal weight range, the inflammatory biomarkers were correlated with HRV parameters in schoolchildren living in the northeastern region of Brazil.
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Resumo Fundamento: Distrofia Muscular de Duchenne (DMD) é uma doença neuromuscular hereditária rara. O acometimento cardíaco inicial pode ser assintomático. Portanto, a avaliação por métodos não invasivos pode auxiliar sua abordagem. Objetivos: Analisar o eletrocardiograma (ECG) e a variabilidade da frequência cardíaca (VFC) do grupo com DMD, e comparar com a do grupo controle pareado por idade. Métodos: Estudo prospectivo com 27 pacientes masculinos com DMD (idade de 11,9 anos) que foram submetidos à avaliação clínica, ECG, ecocardiograma e Holter. ECG (aumento de 200%) foi avaliado por dois observadores independentes. VFC foi feita no domínio do tempo (24 h) e da frequência na posição supina e sentada. O grupo saudável foi de nove pacientes (11,0 anos). Um valor de p < 0,05 foi considerado estatisticamente significante. Resultados: A média da fração de ejeção (FE) foi de 60% (34 a 71%). O coeficiente de Kappa para as medidas do ECG variou de 0,64 a 1,00. Foram verificados aumento da relação R/S em V1 em 25,9%, onda Q patológica em 29,6% e QRS fragmentado em 22,2% em regiões inferior/lateral alta, este com correlação negativa com FE (p = 0,006). Houve baixa VFC, sem influência de nenhuma variável, inclusive tratamento. Com a mudança da posição, houve aumento da FC (p = 0,004), porém não houve alteração da VFC. A relação LF/HF foi de 2,7 na DMD e de 0,7 no controle (p = 0,002). Conclusões: Nos participantes com DMD, as ondas R proeminentes em V1 e alterações nas regiões inferior/lateral alta ocorreram em quase 30% dos casos. Houve menor tônus vagal sem influência das variáveis idade, fração de ejeção, dispersão do QT e tratamento. Apesar do aumento da FC, não houve resposta adequada da VFC com a mudança de posição.
Abstract Background: Duchenne Muscular Dystrophy (DMD) is a rare inherited neuromuscular disease. At first, cardiac involvement may be asymptomatic. Therefore, assessing patients using non-invasive methods can help detect any changes. Objectives: Analyze the electrocardiogram (ECG) test and heart rate variability (HRV) of the DMD group and compare the information with that of the age-matched control group. Methods: A prospective study with 27 male patients with DMD (11.9 years old), who underwent clinical evaluation, ECG, echocardiogram, and Holter monitoring. ECG (200% increase) was assessed by two independent observers. HRV was measured over time (24 h) and in the frequency domain, in the supine and sitting positions. The healthy group consisted of nine patients (11.0 years old). A value of p < 0.05 was considered statistically significant. Results: The mean ejection fraction (EF) was 60% (34 to 71%). The Kappa coefficient for ECG measurements ranged from 0.64 to 1.00. An increase in the R/S ratio in V1 was observed in 25.9% of the subjects, pathological Q wave in 29.6%, and fragmented QRS in 22.2% in inferior/high lateral regions, with a negative correlation with EF (p = 0.006). There was low HRV, without the influence of any variable, including treatment. With the change in position, there was an increase in HR (p = 0.004), but there was no change in HRV. The LF/HF ratio was 2.7 in the DMD group and 0.7 in the control group (p = 0.002). Conclusions: In DMD subjects, prominent R waves in V1 and changes in the inferior/high lateral regions occurred in almost 30% of the cases. Lower vagal tone was observed without the influence of the variables age, ejection fraction, QT dispersion, and treatment. Despite the increase in HR, there was no adequate HRV response to the change in position.
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Introducción: La enfermedad pulmonar intersticial difusa no soporta el ejercicio, debido a la sensación de disnea y fatiga durante el esfuerzo de baja intensidad. La recuperación de la frecuencia cardíaca se relaciona con el desempeño en el test de caminata de los seis minutos. Objetivo: Determinar las diferencias sociodemográficas de la función y la capacidad pulmonar en pacientes con enfermedad intersticial difusa, a partir de la recuperación de la frecuencia cardíaca durante el test de caminata de los seis minutos. Métodos: Se realizó un estudio descriptivo de corte transversal. Se calculó la recuperación de la frecuencia cardíaca a partir de la diferencia entre el final del test y los cinco minutos de la prueba. Se conformaron dos grupos de comparación, anormal versus normal, en variables sociodemográficas de la función pulmonar y la capacidad funcional. Resultados: Se vincularon 38 pacientes en el grupo normal y en el anormal 26. En el primero predominaron la edad de 62,26 ± 15,82 y los hombres (52,6 %); mientras que en el grupo anormal los años promediaron entre 58,77 ± 13,23 y sobresalieron las mujeres (61,5 %). Se presentó un valor p < 0,05 del grupo recuperación de la frecuencia anormal en la distancia recorrida, disnea y fatiga al final, un minuto y a los cinco minutos de culminar el test. Conclusiones: Los pacientes con enfermedad pulmonar intersticial difusa con una recuperación de la frecuencia cardíaca anormal presentaron peores resultados en la distancia recorrida, volumen de oxígeno, los equivalentes metabólicos, disnea y fatiga de los miembros inferiores.
Introduction: Diffuse interstitial lung disease does not tolerate exercise, due to the sensation of dyspnea and fatigue during low-intensity exertion. Heart rate recovery is related to performance in the six-minute walk test. Objective: To determine sociodemographic differences in lung function and capacity in patients with diffuse interstitial lung disease, based on heart rate recovery during the 6-minute walk test. Methods: A descriptive cross-sectional study was performed. Heart rate recovery was calculated from the difference between the end of the test and the five minutes of the test. Two comparison groups were formed, abnormal versus normal, in sociodemographic variables of pulmonary function and functional capacity. Results: 38 patients were included in the normal group and 26 in the abnormal group. In the normal group, age was 62.26 ± 15.82 and men were predominant (52.6 %); while in the abnormal group, age averaged 58.77 ± 13.23 and women were predominant (61.5 %). A p-value < 0.05 of the abnormal frequency recovery group was presented in the distance run, dyspnea at the end, fatigue at the end, 1 minute and at 5 minutes after the culmination of the test. Conclusions: Patients with diffuse interstitial lung disease with abnormal heart rate recovery had worse results in distance run, oxygen volume, metabolic equivalents, dyspnea and lower limb fatigue.
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Abstract Background Firefighters are regularly exposed to stress and have a high incidence of cardiovascular events. Investigating cardiovascular and autonomic reactivity to acute mental stress (AMS) and its association with adiposity may contribute to explaining the increased cardiovascular risk in these professionals. Objectives To evaluate cardiovascular and autonomic reactivity to AMS in firefighters while considering adiposity parameters. Methods This study recorded the blood pressure and heart rate (HR) of twenty-five firefighters (38±8 years) at rest, while performing the Stroop color-word test to induce AMS, and recovery. Cardiac autonomic modulation (HR variability), baroreflex sensitivity (BRS — sequential method), and adiposity (electrical bioimpedance) were assessed. One-way or two-way analysis of variance followed by Tukey's post hoc test and multiple linear regression were performed. The significance level was P<0.05. Results The AMS increased mean arterial pressure (MAP — Δ16±13 mmHg) and HR (Δ14±7 bpm) ( P <0.05). These responses were associated with parasympathetic modulation withdrawal (RMSSD: baseline: 29.8±18 vs. AMS: 21.5±14 ms; High-frequency: baseline: 5.2±1.4 vs. AMS: 4.5±1.3 Ln ms 2 ; P <0.05) and decreased in the Up gain of the baroreflex (baseline: 8.9±5.1 vs. AMS: 6.3±3.0 mmHg/ms; P <0.05). Groups divided by HR reactivity peak showed parasympathetic modulation withdrawal only in firefighters with lower adiposity (RMSSD: baseline: 27.8±17.6 vs. AMS: 14.4±9.2 ms; High-Frequency: baseline: 5.3±1.2 vs. AMS: 3.8±1.4 Ln ms 2 ; P <0.05). Fat percentage (β = -0.499), BRS (β = 0.486), and sympathetic/parasympathetic balance (β = -0.351) were predictors of HR reactivity ( P <0.05). Conclusion Our results demonstrated that HR reactivity to AMS modulated by cardiac vagal withdrawal seems to be influenced by body composition in this group of firefighters.
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Abstract Introduction Specialised literature demonstrates that chronic obstructive pulmonary disease (COPD) has patho-physiological changes that impair cardiac autonomic function and the ability of the cardiovascular system to respond to stimuli. Objective To analyze the correlation between heart rate (HR), peripheral oxygen saturation (SpO2), functional and pulmonary capacity in patients with COPD during the six-minute walk test (6MWT) before and after the pulmonary rehabilitation program (PRP). Methods This is a descriptive and retrospective study, with collection carried out in the PRP database of a university in Vale dos Sinos, Brazil. Results: The sample consisted of 216 patients, classified as having severe COPD, with a predominance of males (57.4%), with a mean age of 65.4 ± 7.9 years. The results showed that at the pre-PRP moment, the HR at the end of the test showed a strong negative correlation (p < 0.01) with SpO2 obtained at the end of the test, and forced expiratory volume in the first second (FEV1). At the post-PRP moment, the HR at the end of the test was strongly negatively cor-related with SpO2 and FEV1 positively, weakly (p < 0.05) with the sensation of dyspnea at the end of the test, and strongly with the distance covered in the 6MWT (6MWD). Conclusion The correlations between HR, FEV1, 6MWD, dyspnea and SpO2 were confirmed, making it evident that as the variables change, HR changes occur to meet the metabolic, oxygenation and ventilatory demands.
Resumo Introdução A literatura evidencia que a doença pulmonar obstrutiva crônica (DPOC) possui características fisiopatológicas que prejudicam a função autonômica cardíaca e a capacidade do sistema cardiovascular em responder aos estímulos. Objetivo Analisar a correlação entre a frequência cardíaca (FC), saturação periférica de oxigênio (SpO2) e capacidade funcional e pulmonar em pacientes com DPOC durante o teste de caminhada seis minutos (TC6), antes e após programa de reabilitação pulmonar (PRP). Métodos Trata-se de um estudo descritivo e retrospectivo, com coleta realizada no banco de dados do PRP de uma universidade do Vale dos Sinos. Resultados A amostra foi composta por 216 pacientes com DPOC grave, com média de idade de 65,4 ± 7,9 anos e predominância do sexo masculino (57,4%). Os resultados evidenciaram que no momento pré-PRP, a FC ao final do teste apresentou correlação negativa forte (p < 0,01) com a SpO2 obtida ao final do teste e volume expiratório forçado no primeiro segundo (VEF1). No momento pós-PRP, a FC ao final do teste se correlacionou negativamente de maneira forte com a SpO2 e VEF1, positivamente de forma fraca (p < 0,05) com a sensação de dispneia pós-teste e forte com a distância percorrida no TC6 (DTC6). Conclusão As correlações entre FC, VEF1, DTC6, dispneia e SpO2 foram confirmadas, ficando evidente que à medida que ocorrem alterações das variáveis, acontecem modificações na FC para suprir a demanda metabólica, ventilatória e de oxigenação.
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Abstract Introduction: Patients with end-stage renal disease often face a challenging routine of hemodialysis, dietary restrictions, and multiple medications, which can affect their hemodynamic function. Home-based, safe, and nonpharmacological approaches such as transcranial direct current stimulation (tDCS) should be combined with conventional treatment. Objective: To assess the safety and feasibility of tDCS on blood pressure and heart rate in patients with end-stage renal disease undergoing hemodialysis. Method: This is a parallel, randomized, sham-controlled trial. Patients undergoing hemodialysis for more than three months were included. The patients received ten non-consecutive 2mA tDCS sessions on the primary motor cortex . Each session lasted 20 minutes. At baseline and after each of the ten sessions, blood pressure and heart rate of the patients were measured hourly for four hours. Results: Thirty patients were randomized to the active or sham group. The mean difference between the groups was calculated as the mean value of the sham group minus the mean value of the active group. Despite there were no statistical changes for all outcomes considering all 10 sessions, we found differences between groups for systolic -10.93 (-29.1;7.2), diastolic -3.63 (-12.4; 5.1), and mean blood pressure -6.0 (-16.3; 4.2) and hear rate 2.26 (-2.5; 7.1). No serious adverse events were found. The active group showed higher blood pressure values at all points, while heart rate was lower in the active group. Conclusion: tDCS is safe and feasible for patients with end-stage renal disease undergoing hemodialysis. Future studies should investigate whether tDCS could potentially induce a hypotensive protective effect during hemodialysis.
Resumo Introdução: Pacientes com doença renal em estágio terminal (DRET) geralmente enfrentam uma rotina desafiadora de hemodiálise, restrições alimentares e diversos medicamentos, podendo afetar sua função hemodinâmica. Abordagens domiciliares, seguras e não farmacológicas, como a estimulação transcraniana por corrente contínua (ETCC), devem ser combinadas com tratamento convencional. Objetivo: Avaliar segurança e viabilidade da ETCC na pressão arterial e frequência cardíaca em pacientes com DRET em hemodiálise. Método: Estudo paralelo, randomizado, controlado por placebo. Foram incluídos pacientes em hemodiálise por mais de três meses. Os pacientes receberam dez sessões não consecutivas de ETCC de 2mA no córtex motor primário. Cada sessão durou 20 minutos. No início do estudo e após cada uma das dez sessões, a pressão arterial e frequência cardíaca dos pacientes foram medidas a cada hora durante quatro horas. Resultados: Trinta pacientes foram randomizados para grupo ativo ou sham. A diferença média entre grupos foi calculada como valor médio do grupo sham menos valor médio do grupo ativo. Apesar de não haver alterações estatísticas para todos os desfechos considerando as 10 sessões, encontramos diferenças entre os grupos para pressão arterial sistólica -10,93 (-29,1; 7,2), diastólica -3,63 (-12,4; 5,1) e média -6,0 (-16,3; 4,2) e frequência cardíaca 2,26 (-2,5; 7,1). Não encontramos eventos adversos graves. O grupo ativo apresentou valores maiores de pressão arterial em todos os pontos, enquanto a frequência cardíaca foi menor no grupo ativo. Conclusão: ETCC é segura e viável para pacientes com DRET submetidos à hemodiálise. Estudos futuros devem investigar se a ETCC pode potencialmente induzir um efeito hipotensor protetor durante a hemodiálise.
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Background and Objective@#Premature ventricular complex (PVC) burden exhibits one of three circadian types, classified as fast-type, slow-type, and independent-type PVC. It is unknown whether PVC circadian types have different heart rate variability (HRV) parameter values. Therefore, this study aimed to evaluate differences in HRV circadian rhythm among fast-, slow-, and independent-type PVC. @*Methods@#This cross-sectional observational study consecutively recruited 65 idiopathic PVC subjects (23 fast-, 20 slow-, and 22 independent-type) as well as five control subjects. Each subject underwent a 24-hour Holter to examine PVC burden and HRV. HRV analysis included components that primarily reflect global, parasympathetic, and sympathetic activities. Repeated measures analysis of variance was used to compare differences in HRV circadian rhythm by PVC type. Results. The average PVC burden was 15.7%, 8.4%, and 13.6% in fast-, slow-, and independent-type idiopathic PVC subjects, respectively. Global, parasympathetic nervous system, and sympathetic nervous system HRV parameters were significantly lower in independenttype PVC versus fast- and slow-type PVC throughout the day and night. Furthermore, we unexpectedly found that tendency towards sympathetic activity dominance during nighttime was only in independent-type PVC.@*Conclusion@#The HRV parameters are reduced in patients with independent-type PVC compared to fast- and slowtype PVC. Future research is warranted to determine possible differences in the prognosis between the three PVC types.
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Complexos Ventriculares Prematuros , Ritmo Circadiano , Sistema Nervoso AutônomoRESUMO
Objective To explore the difference in efficacy of metoprolol versus ivabradine in the treatment of postural orthostatic tachycardia syndrome(POTS)in the elderly after COVID-19 infection.Methods A total of 110 patients diagnosed with POTS at our department from Decem-ber 1,2022 to January 31,2023 were included.According to their drug regimen,they were divided into metoprolol group(62 patients)and ivabradine group(48 patients).On the 28th day of out-patient follow-up,the resting heart rate,heart rate of 10 min of standing,symptom disappearance rate,hospitalization rate,and mortality rate were compared between the two groups.Results On the 28th day of treatment,the resting heart rate and postural heart rate for 10 min were decreased in both groups when compared with the levels at initial diagnosis(P＜0.01).And there were no significant differences in the two types of heart rate between the two groups on the 28th day(71.0±7.0 vs 72.1±7.0,P=0.401;76.5±7.2 vs 77.4±7.6,P=0.573).No obvious differences were observed between the two groups in symptom disappearance rate,hospitalization rate,or mortality rate(88.7％vs 89.6％,3.2％vs2.1％,0％vs 0％,P＞0.05).Conclusion Metoprolol and ivabradine can effectively treat POTS in the elderly patients after COVID-19 infection.
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Objective To evaluate the application value of the second generation snap shot freeze(SSF2)combined with artificial intelligence reconstruction in free heart rate coronary computed tomography angiography(CCTA).Methods The examination data of 37 patients undergoing CCTA were divided into two groups for reconstruction.Group A,reconstruction by artificial intelligence after SSF2 algorithm correction;group B,original images automatically split and multi-phase reconstruction by artificial intelligence.Image quality were compared on volume rendering(VR),curve planar reformation(CPR),maximum intensity projection(MIP)image,subjective evaluation,objective scoring,and signal-to-noise ratio(SNR).Independent samples t-test and Chi-square test were used,and P<0.05 was considered statistically significant.Results There were statistically significant differences in the image quality score and SNR of the two reconstruction methods(P=0.009).Group A scored better,with higher signal intensity,lower noise intensity,and better SNR.The difference in the number of right coronary artery(RCA)analyzable segments between the two groups was statistically significant(P<0.05).The excellent and good rate of subjective evaluation of coronary artery segments in group A RCA(98.6%)was higher than that in group B(69.6%).Conclusion Using SSF2 combined with artificial intelligence reconstruction technology can significantly improve the image quality of CCTA,improve the success rate of CCTA examination,and improve the overall work efficiency.
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Objective:To study the effects of low-dose dexmedetomidine via nasal spray on preoperative anxiety and tracheal intuba-tion induced stress response in elderly patients with maxillofacial surgery using heart rate variability(HRV).Methods:60 elderly pa-tients underwent maxillofacial surgery were randomly divided into the dexmedetomidine group(group D)and the control group(group C).Patients in the group D were treated with nasal spray of dexmedetomidine at 45 min preoperatively.Those in the group C were giv-en the same dose of normal saline spray at the same time.All patients were given intravenous combined with inhalation general anes-thesia.The hemodynamics,HRV index,sedation score and BIS value of the 2 groups of patients were compared at 3 time points,be-fore operation(T0),entrance(T1)and tracheal intubation(T2)respectively.Results:At T1,the average score of Ramsay in group D and group C was 2.8±0.7 and 1.1±0.39,BIS 87.3±6.1 and 97.4±0.5,SD1 20.9±7.0 and 15.4±5.4,SDNN 30.9±6.6 and 37.1±7.0,LF/HF 1.3±0.3 and 2.6±0.4,respectively(P＜O.01).At T2,the average score of SD1 in group D and group C was 10.4±3.5 and 7.7±3.1,SDNN 59.2±6.5 and 70.1±7.1,LF/HF 5.l±0.5 and 7.5±0.5,respectively(P＜0.01).Conclusion:Low-dose dexmedetomidine nasal spray can effectively relieve the preoperative anxiety of elderly patients in maxillofacial surgery and reduce the stress response of tracheal intubation.
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BACKGROUND:Heart rate variability biofeedback is a respiratory training method that uses slow and deep breathing at the resonant frequency to induce rhythmic,high-amplitude oscillations in the cardiovascular system,thereby stimulating and exercising the autonomic and baroreflex.However,current studies have not systematically reviewed how heart rate variability biofeedback modulates the autonomic function and produces effects.There is a lack of public understanding of the mechanism of heart rate variability biofeedback,and its application progress and scheme are not fully understood. OBJECTIVE:To review the existing experimental studies on the effects of heart rate variability biofeedback on symptoms in different populations at home and abroad and to introduce the mechanisms and advances in the application of heart rate variability biofeedback to modulate the autonomic nervous system. METHODS:"Heart rate variability biofeedback,resonance breathing,heart rate variability,autonomic nerve,breathing training,chronic diseases,mental illness,biofeedback"were used as Chinese or English keywords to search in CNKI,WanFang Database,PubMed,and Web of Science.A total of 72 core related papers were included according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION:The body's oscillation system and resonance system are essential for the effectiveness of heart rate variability biofeedback.Oscillations reflect the response to external stimuli and self-regulating reflex systems,while resonances involve synchronous oscillations that result in higher amplitude operations.The balance between sympathetic and parasympathetic nerves is crucial for maintaining a stable internal environment.Autonomic nervous system disorders are associated with reduced heart rate variability and are closely linked to the progression of related diseases.Heart rate variability biofeedback utilizes the resonance characteristics of the cardiovascular system,inducing rhythmic high-amplitude oscillations by employing deep slow breathing at the resonance frequency.This method improves the regulatory function of the sympathetic and parasympathetic system reflexes and enhances the balance regulation between the two systems.Two major mechanisms of cardiovascular system resonance are the baroreflex closed-loop pathway and respiratory sinus arrhythmia.These mechanisms,along with the unique delay of baroreflex,result in a 0° phase angle oscillation between heart rate and respiration and a 180° phase angle oscillation between blood pressure and respiration during breathing at the resonant frequency rhythm.Periodically stimulating the human cardiovascular oscillation system through this method is an easy-to-operate and effective training approach.Currently,heart rate variability biofeedback is mainly applied in the fields of mental illness,chronic disease,and sports.However,the intervention mechanism and efficacy are unclear,the intervention content,frequency and duration are varied,and there are limited review studies on the intervention methods tailored to different types of individuals.As a non-drug and non-invasive intervention,heart rate variability biofeedback can significantly increase heart rate variability,regulate the balance between sympathetic and parasympathetic nerves,and improve the stability and adaptability of the autonomic nervous system.In the future,it is suggested to investigate the mechanisms and potential applications of the pathways of the heart rate variability biofeedback that induce cardiovascular resonance.It is also recommended to incorporate long-term follow-ups to assess the sustained value of heart rate variability biofeedback in various fields.This would provide new directions and strategies for the comprehensive treatment of complex diseases.
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Objective To explore the clinical effect of clinical observation of supplemented wendan decoction combined with Western medicine in treating insomnia accompanied by anxiety and depression in phlegm-heat internal disturbance syndrome.Methods A total of 120 cases of insomnia with anxiety and depression comorbiditis with phlegm heat disturbance syndrome were randomly divided into control group and treatment group,60 cases in each group.The control group was given escitalopram oxalate tablet combined with dexzopiclonone tablet,and the observation group was given added Wendan decoction on the basis of the control group.Both groups were treated continuously for 6 weeks.Polysomnography monitoring parameters and heart rate variability were compared between the two groups during baseline period and visit 2(baseline period+3 months).Scale scores of the two groups were compared during baseline period,visit 1(baseline period+6 weeks)and visit 2.The content of heart rate variability includes:time domain analysis(standard deviation of normal interval(SDNN),square root of the square sum of the mean of the difference between adjacent normal interval(RMSSD)and frequency domain analysis(LF,HF,LF/HF).The scale scores included the Pittsburgh Sleep Quality Index(PSQI)and Insomnia Severity Index(ISI)to assess sleep status,and the Hamilton Depression Scale(HAMD),Hamilton Anxiety Scale(HAMA),Self-assessment Scale for Depression(PHQ-9)and Generalized Anxiety Disorder Scale(GAD-7)to assess anxiety and depression status.Results(1)Polysomnography monitoring:the wake time of observation group was significantly shorter than that of control group,the number of awakenings was significantly less than that of control group,and the percentage of N3 and REM was significantly higher than these of control group(P＜0.05).(2)Heart rate variability:RMSSD and HF values in the observation group were significantly higher than those in the control group,and LF/HF values were significantly lower than those in the control group(P＜0.05).(3)In terms of sleep:during the interview,PSQI total score,sleep quality,hypnotic drugs and daytime dysfunction in the observation group were significantly lower than those in the control group(P＜0.05);At the 3 months,the sleep quality,hypnotic drugs and daytime dysfunction in the observation group were significantly lower than those in the control group(P＜0.05).In terms of emotion:HAMA,HAMD and GAD-7 scores were significantly lower than those of control group at 6 weeks(P＜0.05);At the 3 months,HAMA and GAD-7 scores were significantly lower than those of control group(P＜0.05).Conclusion Supplemented Wendan decoction combined with western medicine can obviously optimize the sleep structure of insomnia patients with anxiety and depressionof phlegm-heat disturbance syndrome,improve sleep continuity and deepen sleep depth,and improve parasympathetic functional activities,contribute to sympathetic parasympathetic balance,can improve insomniaand depression symptoms recently,and significantly improve anxiety symptoms in the short term,with good safety.
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Objective:To evaluate the value of the ROX index [blood oxygen saturation (SpO 2)/fraction of inspiration O 2 (FiO 2)/respiratory rate (RR)], ROX-heart rate (HR) index (ROX index/HR × 100), modified ROX (mROX) index [partial pressure of oxygen in the blood (PaO 2)/FiO 2/RR], and mROX-HR index (mROX index/HR × 100) in predicting prognosis for patients with acute respiratory distress syndrome (ARDS) treated with high-flow nasal cannula oxygen therapy (HFNC). Methods:The clinical data of 100 patients with ARDS who received HFNC between January 2018 and December 2022 at The Third People's Hospital of Hubei Province, Jianghan University, were retrospectively analyzed. These patients were divided into two groups based on whether HFNC treatment was successful or not: a success group with 65 patients and a failure group with 35 patients. The differences in the ROX index, ROX-HR index, mROX index, and mROX-HR index in the observation group were observed at the designated time points: 2, 12, and 24 hours after HFNC treatment. Receiver operating characteristic (ROC) curves were utilized to evaluate the value of ROX index, ROX-HR index, mROX index, and mROX-HR index in predicting the success or failure of HFNC treatment at 2, 12, and 24 hours. Cutoff values were determined.Results:There were no significant differences in age, gender, body mass index, Acute Physiology and Chronic Health Evaluation (APACHE II) score, Sequential Organ Failure Assessment score, or the proportions of underlying diseases and pulmonary causes between the success and failure groups (all P > 0.05). Furthermore, there were no significant differences in baseline HR, RR, FiO 2, SpO 2, partial pressure of carbon dioxide (PaCO 2), PaO 2, pH, lactate, oxygenation index, ROX index, mROX index, ROX-HR index, or mROX-HR index between the two groups (all P > 0.05). The ROX index in the success group at 2, 12, and 24 hours after HFNC treatment was 6.86 ± 1.09, 6.31 ± 1.61, and 8.24 ± 2.29, respectively. These values were significantly higher than those in the failure group (6.36 ± 0.67, 5.65 ± 1.44, and 5.41 ± 0.84) at the corresponding time points ( F = 5.97, 4.04, 49.40, all P < 0.05). At 2, 12, and 24 hours after HFNC treatment, the mROX index in the success group was 5.94 ± 1.28, 5.74 ± 1.23, and 8.51 ± 2.64, respectively. These values were significantly higher than those in the failure group (5.26 ± 0.74, 4.80 ± 0.97, 4.81 ± 1.17) at the corresponding time points ( F = 8.23, 15.38, 61.79, all P < 0.05). At 2, 12, and 24 hours after HFNC treatment, the ROX-HR index in the success group was 6.53 ± 1.32, 6.85 ± 1.44, and 7.57 ± 1.47, respectively. These values were significantly higher than those in the failure group (5.79 ± 1.04, 5.87 ± 1.03, 5.57 ± 0.63) at the corresponding time points ( F = 8.28, 12.61, 58.34, all P < 0.05). At 2, 12, and 24 hours after HFNC treatment, the mROX-HR index in the success group was 6.11 ± 1.30, 6.86 ± 1.13, and 7.79 ± 1.79, respectively. These values were significantly higher than those in the failure group (5.20 ± 1.06, 5.66 ± 1.46, 4.92 ± 0.90) at the corresponding time points ( F = 12.60, 20.87, 78.56, all P < 0.05). The receiver operating characteristic curve analysis revealed that the optimal thresholds were 6.56, 6.02, 6.24, and 5.25 for the ROX index, mROX index, ROX-HR index, and mROX-HR index, respectively. The area under the curve (AUC) values were 0.63, 0.66, 0.68, and 0.72, with sensitivity of 55.4%, 47.7%, 56.9%, and 76.9%, and specificity of 71.4%, 91.4%, 77.1%, and 62.9%, respectively. At 12 hours after treatment, the optimal thresholds were 6.09, 5.53, 6.52, and 5.99, with AUC values of 0.62, 0.70, 0.67, and 0.80, sensitivity of 55.4%, 53.8%, 61.5%, and 80.0%, and specificity of 74.3%, 77.1%, 71.4%, and 74.3%, respectively. At 24 hours after treatment, the optimal thresholds were 6.23, 6.4, 5.99, and 6.22, with AUC values of 0.88, 0.90, 0.91, and 0.93, sensitivity of 81.5%, 80.0%, 87.7%, and 83.1%, and specificity of 91.4%, 94.3%, 80.0%, and 91.4%, respectively. Conclusion:The use of the ROX index, mROX index, ROX-HR index, and mROX-HR index can aid in predicting the prognosis of ARDS patients. The predictive value of these indices increases as treatment time progresses. The mROX-HR index offers marked advantages during the initial stages of treatment and could serve as a reliable early predictor.
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Objectives:To investigate the efficacy of dexmedetomidine for foraminal endoscopic surgery.Methods:A total of 75 patients with lumbar disc herniation who received treatment at the First Affiliated Hospital of Anhui Medical University between September 2020 and May 2021 were included in this study. Using a case-control study method, these patients were divided into three groups according to different treatment methods, with 25 patients in each group. The three groups underwent a single-segment unilateral approach for foraminal endoscopic surgery. Group A received simple process infiltration anesthesia, while Group B and Group C received a pump injection of 0.5 μg/kg/h dexmedetomidine for 20 minutes prior to surgery. Group B underwent post-surgical anesthesia adjustments, which involved joint process infiltration anesthesia that was seamlessly integrated with a pump-administered dexmedetomidine infusion at a rate of 0.4 μg/kg/h throughout the surgical procedure. Group C received joint process infiltration anesthesia that was seamlessly integrated with a pump-administered dexmedetomidine infusion at a rate of 0.6 μg/kg/h throughout the surgical procedure. Vital signs, sedation status, sedation score, length of hospital stay, pain score (VAS) immediately after surgery, pain scores at 3 and 6 hours after surgery, and changes in vital signs at different points during surgery were compared among the three groups.Results:There were no significant differences in age, sex, or surgical segment among the three groups (all P > 0.05). The postoperative length of hospital stay in Groups A, B, and C was (5.12 ± 1.15) days, (3.02 ± 0.42) days, and (3.82 ± 0.54) days, respectively ( F = 32.04, P < 0.01). At the beginning of surgery, the sedation scores in Groups A, B, and C were (1.22 ± 0.29) points, (1.28 ± 0.36) points, and (1.46 ± 0.38) points, respectively ( F = 3.28, P < 0.05). At 30 minutes after surgery, the sedation scores in the three groups were (2.12 ± 0.22) points, (2.16 ± 0.24) points, and (2.20 ± 0.24) points, respectively ( F = 3.72, P < 0.01). Immediately after surgery, the Visual Analogue Scale (VAS) scores in the three groups were (3.52 ± 0.33) points, (2.92 ± 0.55) points, and (2.82 ± 0.54) points, respectively ( F = 15.16, P < 0.01). At 3 hours after surgery, the VAS scores in the three groups were (3.64 ± 0.39) points, (2.60 ± 0.58) points, and (2.74 ± 0.54) points ( F = 30.47, P < 0.01). At 6 hours after surgery, the VAS scores in the three groups were (3.78 ± 0.43) points, (2.52 ± 0.47) points, and (2.74 ± 0.52) points, respectively ( F = 49.90, P < 0.01). There were significant differences in VAS score, heart rate, and mean arterial pressure among the three groups during articular process puncture, cannula expansion of the intervertebral foramen, and capture of the perinerve protrusion nucleus pulposus ( F = 34.59, 148.65, 164.08, 5.08, 10.81, 38.06, 43.62, 37.46, and 38.76, all P < 0.05). Conclusion:Preoperative dexmedetomidine can effectively maintain hemodynamic stability, ensure sedation levels, reduce postoperative pain, and accelerate patient recovery after surgery.