How did coronavirus disease 2019 affect autonomic balance in young individuals? Analysis by heart rate variability

SUMMARY OBJECTIVE: The aim of this study was to demonstrate the effect of coronavirus disease 2019 on the cardiovascular autonomic system using heart rate variability in young individuals. METHODS: The study was designed retrospectively by scanning the 24-h Holter electrocardiography records of patients who applied to the Ankara Abdurrahman Yurtaslan Oncology Education and Research Hospital Cardiology outpatient clinic. The study group consisted of 492 patients under the age of 40 years, who did not have additional comorbidities or medication use and had prolonged symptoms after coronavirus disease 2019 during the pandemic. The control group, including 401 patients, was determined during the pre-pandemic period (before December 2019). Heart rate variability parameters were evaluated by scanning the 24-h Holter electrocardiography records of the patients and compared with the non-coronavirus disease 2019 group. RESULTS: The median age of participants was 30 years. Standard deviation of normal RR intervals (SDNN) ≤100 ms was more prevalent in the study group (27 (6.7%) vs 73 (14.8%), p<0.001). In univariate logistic regression analysis, the presence of coronavirus disease 2019 [(OR 2.41, 95%CI 1.52-3.83), p<0.001] and age [(OR 1.04, 95%CI 1.01-1.07), p=0.016] had a significant effect on the probability of SDNN≤100. In multivariate logistic regression analysis, the presence of coronavirus disease 2019 [(OR 2.42, 95%CI 1.52-3.85), p<0.001] and age [(OR 2.42, 95%CI 1.52-3.85), p=0.016] had a significant effect on the probability of SDNN≤100. Frequency domain measures such as, high-frequency values were significantly higher in the study group (p=0.029). The study group's low-frequency/high frequency ratio was significantly lower (p=0.019). The low-frequency/high-frequency ratio's cut-off value was ≤2.77. for determining the differentiation between coronavirus disease 2019 positive and negative cases in the receiver operating characteristic analysis. The sensitivity rate was 80.7%. The area under the curve value is 0.546 (p=0.019). CONCLUSION: This study showed that coronavirus disease 2019 causes reduced heart rate variability and increased parasympathetic activity in young patients. This may explain the prolonged symptoms after coronavirus disease 2019 infection.

A cross-sectional descriptive study of clinical autonomic dysfunction in diabetic peripheral neuropathy

Background: Adults having type 2 diabetes mellitus satisfying inclusion and exclusion criteria will be included. Consent of those who fit into inclusion criteria taken. 100 patients were analysed on the basis of history, clinical presentations, investigations. Patients presenting with signs and symptoms of neuropathy were accessed by nerve conduction studies (NCV), autonomic testing, heart rate variation with deep breathing, blood pressure response to standing. Arterial blood gas analysis, and CT /MRI also done. Methods: 100 patients of type 2 diabetes were taken and study of autonomic dysfunction was done for 3 months across tertiary health care centre. Results: Out of 100 diabetic patients under study 54 patients (54%) had diabetic neuropathy. Out of these 54, distal sensory motor neuropathy- most common (77%), sensory neuropathy- 24%. Axonal neuropathy was more prevalent than demyelinating neuropathy. Out of 100, 51 (51%) patients have autonomic neuropathy. Peripheral neuropathy was most common complication in which distal sensory motor polyneuropathy were common. Most common symptom of autonomic neuropathy was postural dizziness followed by erectile dysfunction. Conclusions: Most common complication of type 2 DM is neuropathy. Most common neuropathy was distal sensory motor polyneuropathy whereas most common symptom of diabetic neuropathy was postural dizziness. Other autonomic dysfunction was change in blood pressure and heart after standing.

Análise Comparativa do ECG com o Holter na avaliação da Frequência Cardíaca na Insuficiência Cardíaca com Fração de Ejeção Reduzida e Ritmo Sinusal / Comparative Analysis of ECG and Holter Monitoring in the Assessment of Heart Rate in Heart Failure with Reduced Ejection Fraction and Sinus Rhythm

Resumo Fundamento A frequência cardíaca (FC) na insuficiência cardíaca com fração de ejeção reduzida (ICFEr) e ritmo sinusal apresenta valor prognóstico. Entretanto, o método de mensuração é debatido na literatura. Objetivos Comparar em pacientes com ICFEr e ritmo sinusal a FC no Holter com três eletrocardiogramas de repouso: ECG1, ECG2 e ECG3. Metodologia Estudo transversal com 135 pacientes portadores de insuficiência cardíaca com fração de ejeção ≤ 40% e ritmo sinusal. A FC foi avaliada por ECG e Holter. Análises incluíram o coeficiente de correlação intraclasse (CCI), regressão robusta, raiz do erro quadrático médio, Bland-Altman e a área sobre a curva ROC. Adotou-se nível de significância de 0,05 e o ajuste de Bonferroni-Holm para minimizar erros tipo I. Resultados As medianas [intervalo interquartil] de idade e fração de ejeção foram de 65 anos [16] e 30% [11], respectivamente. O CCI dos 3 ECG foi de 0,922 (intervalo de confiança de 95%: 0,892; 0,942). Os coeficientes de regressão robusta para ECG1 e ECG3 foram 0,20 (intervalo de confiança de 95%: 0,12; 0,29) e 0,21 (intervalo de confiança de 95%: 0,06; 0,36). O R2 robusto foi de 0,711 (intervalo de confiança de 95%: 0,628; 0,76). Na análise de concordância de Bland-Altman, os limites de concordância foram de −17,0 (intervalo de confiança de 95%: −19,0; −15,0) e 32,0 (intervalo de confiança de 95%: 30,0; 34,0). A área sob a curva ROC foi de 0,896 (intervalo de confiança de 95%: 0,865; 0,923). Conclusão A FC do ECG mostrou alta concordância com a FC do Holter, validando seu uso clínico em pacientes com ICFEr e ritmo sinusal. Contudo, a concordância foi subótima em um terço dos pacientes com FC inferior a 70 bpm pelo ECG, devendo ser considerada a realização de Holter neste contexto.

Abstract Background Heart rate (HR) has shown prognostic value in patients with heart failure with reduced ejection fraction (HFrEF) and sinus rhythm. However, the method of measurement is debated in the literature. Objectives To compare HR on Holter with 3 resting electrocardiograms (ECG1, ECG2, and ECG3) in patients with HFrEF and sinus rhythm. Methods This was a cross-sectional study with 135 patients with heart failure with ejection fraction ≤ 40% and sinus rhythm. HR was assessed by ECG and Holter. Analyses included intraclass correlation coefficient (ICC), robust regression, root mean squared error, Bland-Altman, and area under the receiver operating characteristic (ROC) curve. A significance level of 0.05 and Bonferroni-Holm adjustment were adopted to minimize type I errors. Results The median [interquartile range] age and ejection fraction were 65 years [16] and 30% [11], respectively. The ICC of the 3 ECGs was 0.922 (95% confidence interval: 0.892; 0.942). The robust regression coefficients for ECG1 and ECG3 were 0.20 (95% confidence interval: 0.12; 0.29) and 0.21 (95% confidence interval: 0.06; 0.36). The robust R2 was 0.711 (95% confidence interval: 0.628; 0.76). In the Bland-Altman agreement analysis, the limits of agreement were −17.0 (95% confidence interval: −19.0; −15.0) and 32.0 (95% confidence interval: 30.0; 34.0). The area under the ROC curve was 0.896 (95% confidence interval: 0.865; 0.923). Conclusion The HR on ECG showed high agreement with the HR on Holter, validating its clinical use in patients with HFrEF and sinus rhythm. However, agreement was suboptimal in one third of patients with HR below 70 bpm on ECG; thus, 24-hour Holter monitoring should be considered in this context.

The utility value of ROX index and modified ROX index in determining the efficiency of HFNC in children admitted with respiratory distress

Background: The ROX index is defined as the ratio of SpO2/FiO2 to respiratory rate. The modified ROX index or ROX-HR index is defined as the ratio of ROX index/heart rate�0. The aim of the study was to determine the utility of the ROX index and the modified ROX index as predictors of initiation and efficiency of HFNC in children admitted with respiratory distress.Methods: This prospective observational study included 133 children with respiratory distress, who received HFNC. The ROX index, and modified ROX index were measured, and outcomes were recorded.Results: Total number of study subjects were 133. Statistically significant increase was seen in ROX index and modified ROX index at follow up (p value<0.05). Interpretation of the area under the ROC curve showed that the performance of ROX index and modified ROX index at �hour was outstanding. ROX Index and modified ROX Index at a Cut-off of ?4.7959 and ?2.5579 respectively at initiation i. e.; at �hour predicted HFNC requirement. In prediction of HFNC requirement ROX index at �hour had a sensitivity, specificity, positive predictive value, and negative predictive value of 88.24%, 87.84%, 93%, and 80.2% respectively, and modified ROX index had 78.68%, 93.24%, 95.5%, and 70.4% respectively. Low ROX and modified ROX indices at �hour predicted prolonged ICU and hospital stays, as well as extended HFNC duration.Conclusions: Both ROX index, and modified ROX index were good predictors of HFNC requirement.

Hemodynamic response to sub-anesthetic doses of ketamine for postoperative pain: systematic review / Respuesta hemodinámica a dosis subanestésicas de ketamina en dolor posoperatorio: revisión sistemática

Abstract Introduction: Low-dose ketamine infusions have shown analgesic effectiveness for the management of postoperative pain. The impact of low-dose ketamine infusions on cardiovascular response is dose-dependent and requires a better knowledge about its effects on this population. Objective: To conduct a systematic review to describe changes in systolic, diastolic and mean arterial pressure, and heart rate 24, 48 and 72 hours after surgery. Methods: Randomized, controlled trials were reviewed in the Cochrane Library, PubMed, EMBASE, SciELO, Lilacs and grey literature on low-dose ketamine infusions for the study variables. The quality of the studies was assessed using the Cochrane's risk of bias tool. Results: Six randomized, controlled trials with 641 patients were included. Low-quality evidence was found suggestive of a lack of certainty of any significant differences in the systolic blood pressure variables at 24 hours (mean standard deviation -1.00, 95 % CI: -7.27 to 5.27). A statistically significant higher mean heart rate at 24 hours was identified in the low-dose ketamine infusion group, (mean standard deviation 1.64 95 % CI: 0.38 to 2.90) which did not reach clinical significance. A lower pain level and less use of opioids was identified in the low-dose ketamine infusion group. Conclusions: Low quality evidence was found, suggesting that low-dose ketamine infusions are not associated with significant changes in blood pressure or heart rate 24 - 48 hours after surgery. It is important to individualize cardiovascular risk for each case, before initiating treatment.

Resumen Introducción: Las infusiones en dosis bajas de ketamina han mostrado eficacia analgésica en el manejo del dolor posoperatorio. El impacto de las infusiones en dosis bajas de ketamina en la respuesta cardiovascular es dosisdependiente y requiere un mejor conocimiento de sus efectos en esta población. Objetivo: Realizar una revisión sistemática para describir los cambios en la presión arterial sistólica, presión arterial diastólica, presión arterial media, frecuencia cardiaca a las 24, 48 y 72 horas del posoperatorio. Métodos: Se revisaron ensayos controlados aleatorizados en Cochrane Library, PubMed, EM-BASE, SciELO, Lilacs y literatura gris de infusiones en dosis bajas de ketamina para las variables del estudio. La calidad de los estudios se evaluó usando la herramienta de riesgo de sesgos de Cochrane. Resultados: Se incluyeron seis ensayos controlados aleatorizados con 641 pacientes. Se encontró evidencia de baja calidad sugestiva de ausencia de certeza de diferencias significativas en las variables presión arterial sistólica a las 24 horas (diferencia de medias estandarizada -1,00, IC95 %: -7,27 a 5,27). Para las 24 horas se halló una media de frecuencia cardiaca mayor en el grupo de infusiones en dosis bajas de ketamina, estadísticamente significativa (diferencia de medias estandarizada 1,64 IC95 %: 0,38 a 2,90) sin alcanzar significancia clínica. Se encontró menor nivel de dolor y consumo de opioides en el grupo de infusiones en dosis bajas de ketamina. Conclusiones: Se encontró evidencia de baja calidad, sugestiva de que las infusiones en dosis bajas de ketamina no se asocian a cambios significativos en la presión arterial o frecuencia cardiaca a las 24-48 horas en el posoperatorio. Es importante individualizar el riesgo cardiovascular para cada caso previo al inicio del tratamiento.

Determinants of physical performance and physiological responses during an Official cross-country marathon of mountain-biking (Xcm-Mtb) / Determinantes del rendimiento físico y las respuestas fisiológicas durante una maratón oficial de bicicleta de montaña a través del campo (XCM-MTB) / Determinantes do desempenho físico e as respostas fisiológicas durante uma maratona oficial de mountain bike cross-country (Xcm-Mtb)

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.

The effect of hypokalemia in pregnancy on fetal heart rate

Hypokalemic myopathy can cause anything from weakness and numbness to total paralysis. The cause could be acquired or congenital. It is distinguished by low potassium levels (<3.5 meq/L) and severe muscle weakness. We present a case of 30-year-old multigravida at 31 weeks of gestation with malnourished condition, who came with acute onset of weakness of both legs. She was diagnosed to have hypokalemic paralysis with potassium levels of 1.5 meq/L. The medical profile remitted promptly on intravenous potassium replacement. Pregnancy was continued till 37 weeks with oral potassium supplements and regular monitoring of serum potassium levels.

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.

Evaluation of adaptive capabilities of students of different nationalities: cross sectional study

Background: The autonomic nervous system actively regulates the body's reactions to various external and internal factors, ensuring physiological balance in a person. Advances in information technology now allow for a dependable and non-intrusive examination of this system through an in-depth analysis of heart rate variability. This approach is not only a recognized instrument in cardiac studies but is also growing in its utilization for numerous clinical purposes. This overview details the foundational theories and practical uses of this evolving method. The purpose of the study is to study the adaptive reserves and indicators of autonomic regulation in students of different nationalities. Methods: We conducted a cross sectional study of 110 students studying in Grodno State Medical University using photoplethysmography method via an app 揚ulse HRV攄uring the period of December 2022- February 2023. The students were grouped into three groups: Group 1 being Southeast Asian students, Group 2 being Nigerian students and Group 3 being Belarussian students. Results: As a result of the analysis, it was found that AP in group 2 was significantly different from groups 1 and 3. At the same time endurance coefficient was above norm in all groups, which indicated a weakening of the cardiovascular system, while in students from group 2 it was significantly less than in groups 1 and 3. Conclusions: Students from Nigeria have significantly higher adaptive reserves than students from Belarus and Southeast Asia, which may be due to the prevalence of increased tone of the parasympathetic nervous system.

Efecto de la musicoterapia en signos vitales y dolor posoperatorio inmediato / Effect of music therapy on vital signs and immediate postoperative pain

Resumen Objetivo: Evaluar el efecto de la musicoterapia en los signos vitales y el dolor posoperatorio inmediato en pacientes hospitalizados. Metodología: Estudio prospectivo, con una muestra de 80 pacientes divididos en dos grupos (grupo control y grupo de intervención). Al grupo de intervención se le brindo terapia musical a base de música tipo zen en un periodo de 20 minutos, después de una hora se realizó el registro de signos vitales y el resultado de la escala análoga del dolor. Prueba estadística T de Student con significancia estadística. Resultados: Al realizar la comparación entre ambos grupos de estudio se observó una t=0.3 para la frecuencia cardiaca, t=0.9 para la frecuencia respiratoria, presión arterial media con t=0.4 y una Z=0.7 para la escala análoga del dolor. Limitaciones: Preferencia musical en los participantes del estudio. Originalidad: Aplicación clínica en el dolor. Conclusiones: Existe un efecto benéfico en los signos vitales y el dolor posoperatorio inmediato con el empleo de musicoterapia, sin embargo, no se demostró diferencia estadísticamente significativa al comparar ambos grupos de estudio debido probablemente al buen control de la terapia analgésica indicada al paciente.

Abstract Objective: To evaluate the effect of music therapy on vital signs and immediate postoperative pain in hospitalized patients. Methodology: Prospective study, with a sample of 80 patients divided into two groups (control group and intervention group), the intervention group was given musical therapy based on Zen-type music in a period of 20 minutes, 1 hour after Vital signs were recorded and the result of the pain analog scale, Student's t statistical test with statistical significance. Results: When making the comparison between both study groups, a t=0.3 was observed for heart rate, t=0.9 for respiratory rate, mean arterial pressure with t=0.4 and a Z=0.7 for the analog scale of pain. Limitations: Musical preference in study participants. Originality: Clinical application in pain. Conclusions: There is a beneficial effect on vital signs and immediate postoperative pain with the use of music therapy, however, no statistically significant difference was demonstrated when comparing both study groups, probably due to the good control of the analgesic therapy indicated to the patient.

Application of the second generation snap shot freeze combined with artificial intelligence in free heart rate coronary CT angiography / 实用放射学杂志

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.

Clinical evaluation of preoperative nasal spray of low-dose dexmedetomidine in elderly patients by heart rate variability analysis / 实用口腔医学杂志

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.

The mechanism and application of heart rate variability biofeedback regulation of the autonomic nervous system / 中国组织工程研究

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.

Efficacy of metoprolol versus ivabradine in treatment of POTS in elderly patients after COVID-19 infection / 中华老年心脑血管病杂志

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.

Impact of autonomic nerve function on motor function in patients with post-stroke depression / 中国康复理论与实践

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.

Predictive value of systolic pulmonary artery pressure on autonomic nerve excitation in 186 patients with valvular disease: A prospective study / 中国胸心血管外科临床杂志

@#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.

Heart rate variability analysis to investigate autonomic nervous system activity among the three premature ventricular complex circadian types: An observational study

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.

Clinical Observation of Supplemented Wendan Decoction Combined with Western Medicine in Treatment of Insomnia Accompanied by Anxiety and Depression in Phlegm-heat Internal Disturbance Syndrome / 医药导报

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.

Value of modified ROX index in predicting the prognosis of acute respiratory distress syndrome treated with high-flow nasal cannula oxygen therapy / 中国基层医药

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.