Non-linear analysis of heart rate variability during deep breathing at 0.1 Hz frequency

Background: Heart rate variability (HRV) analysis is an important tool to assess the cardiac autonomic regulation in health and disease. Time-domain and frequency-domain analyses are linear methods that are traditionally used for HRV analysis. Application of non-linear methods in HRV analysis has been shown to provide additional information and has been found to be useful in predicting complications and mortality in cardiovascular disease conditions. HRV analysis during deep breathing is commonly used to assess the integrity and extent of the parasympathetic control of the heart. Aim and Objectives: This study aims to analyze the HRV during deep breathing at 0.1 Hz frequency, 6 breaths/minute using non-linear methods and to see whether they correlate with the time-domain measures of HRV. Materials and Methods: Twelve healthy volunteers performed deep slow breathing at 0.1 Hz frequency for 5 min following recorded prompts. In the time domain, mean heart rate (MHR), SDNN, RMSSD, and pNN50 during baseline and deep breathing were measured. In the non-linear domain, approximate entropy (AppEn), sample entropy (SampEn), and detrended fluctuation analysis DFA (?1) were calculated. The quantitative measures of the Poincare plot, namely, SD1, SD2, and SD2/SD1, which are known to provide linear information, were also estimated. Wilcoxon’s signed-rank test was used to compare the baseline parameters with those of deep breathing. Spearman’s correlation was used to assess the correlation between the parameters obtained from the different methods. Results: There was no significant change in the MHR, RMSSD, pNN50, and SD1 during 0.1 Hz deep breathing while SDNN, SD2, SD2/SD1, and DFA?1 showed a significant increase. Furthermore, 0.1 Hz breathing decreased the AppEn and SampEn measures of HRV. There was a strong correlation among SDNN, RMSSD, pNN50, SD1, SD2, SD2/SD1, and DFA?1, but there was no correlation between any of the above measures and the non-linear measures AppEn and SampEn. Conclusion: While the non-linear measure DFA?1 correlates well with time domain measures of HRV and the quantitative measures of the Poincare plot during 0.1 Hz breathing, AppEn and SampEn do not show such correlation. Instead, they decrease significantly when breathing is voluntarily controlled at 6 breaths/min.

Coautoria institucional na produção científica brasileira sobre hanseníase: uma análise a partir da base de dados Web of Science / Institutional co-authorship in Brazilian scientific production on leprosy: an analysis based on the Web of Science database / Coautoría institucional en la producción científica brasileña sobre lepra: un análisis de la base de datos Web of Science

A colaboração científica entre pesquisadores, instituições e países tem despertado o interesse de estudiosos da ciência da informação que desejam conhecer as relações estabelecidas entre os atores envolvidos, a dinâmica e a evolução dos padrões sociais na comunicação científica. Por meio de análise bibliométrica, este estudo objetiva visualizar a rede de colaboração científica entre a comunidade discursiva que conduz pesquisas sobre hanseníase no Brasil, por meio das relações de coautoria institucional. As características da colaboração foram estudadas a partir da coautoria de 498 artigos indexados na base de dados Web of Science no período de 2016 a 2020. As análises revelam que parte significativa dos artigos foi publicada por um grupo reduzido de instituições e que as universidades, apesar de maior número, possuem publicações mais pulverizadas e não ocupam a centralidade da rede, que é dominada por institutos de pesquisa, que concentram grande número de publicações em poucas unidades.

Scientific collaboration between researchers, institutions and countries has aroused the interest of Information Science scholars who want to know the relationships established between the actors involved, the dynamics and evolution of social standards in scientific communication. Through bibliometric analysis, this study aims to visualize the network of scientific collaboration between the discursive community that conducts research on leprosy in Brazil through institutional co-authoring relationships. Collaboration characteristics were studied based on the co-authorship of 498 articles indexed in the Web of Science database in the period 2016-2020. The analyzes reveal that a significant part of the articles was published by a small group of institutions and that, despite the greater number, the universities have more widely distributed publications and don't occupy the centrality of the network, which is dominated by research institutes, which concentrate a large number of publications in a few units.

La colaboración científica entre investigadores, instituciones y países ha despertado el interés de los estudiosos de las Ciencias de la Información que quieren conocer las relaciones que se establecen entre los actores involucrados, la dinámica y evolución de los estándares sociales en la comunicación científica. A través del análisis bibliométrico, este estudio tiene como objetivo visualizar la red de colaboración científica entre la comunidad discursiva que realiza investigaciones sobre la lepra en Brasil a través de relaciones institucionales de coautoría. Las características de la colaboración fueran estudiadas a partir de la coautoría de 498 artículos indexados en la base de datos de Web of Science en el período de 2016 hasta 2020. Los análisis revelan que una parte importante de los artículos fue publicada por un grupo reducido de instituciones y que las universidades, aunque en mayor número, tienen publicaciones más dispersas y no ocupan la centralidad de la red, que es dominada por institutos de investigación, que concentran un gran número de publicaciones en pocas unidades.

Parameter Identification Algorithm of Lumped Parameter Model in the Circle of Willis / 医用生物力学

Objective To explore the application of three parameter identification methods (impedance modulus curve method, impedance component method, and genetic algorithm) in solving parameter identification problem of the 11-element lumped parameter model in the circle of Willis. Methods Using the flow and pressure waveforms of the internal carotid arteries and vertebral arteries on both sides as inlet conditions, parameter values of the model under normal and bilateral vertebral artery stenosis conditions were calculated. The recognition algorithm was verified by using Simulink models, and finally the stability of the recognition algorithm was verified by adding a certain noise to the flow. Results Under normal circumstances, the proximal resistances obtained by the impedance modulus curve method were larger, and the resistances of the anterior communicating artery obtained by the impedance component method were larger. The genetic algorithm could obtain relatively reasonable model parameter values. In the case of vertebral artery stenosis on both sides, the impedance modulus curve method could obviously get the results of the increasement in proximal resistances of the posterior circulation, but the results obtained by the impedance component method and the genetic algorithm mainly lied in that the distal resistance had a larger increase. Conclusions There are still differences between the pressure data calculated by the parameters identified by the above three methods and the actual data, which are considered as modeling errors, source data errors and calculation errors. The impedance modulus curve method has a certain effect in distinguishing changes of the proximal and distal resistances, but there exist large errors in identification of some parameters. The impedance component method can identify the parameters, but this method is unstable with large calculation errors. Genetic algorithm can obtain a better approximate solution, but it has certain problems in distinguishing vertebral artery stenosis. The combination of impedance modulus curve method and genetic algorithm may play a better role in future application of this model for disease diagnosis.

Aproximación al Análisis de Dominio (AD) desde la investigación en Bibliotecología y Ciencia de la Información / Approach to Domain-analysis from Library and Information Science research

RESUMEN Este artículo tiene como objetivo presentar un marco teórico que emergió en las últimas décadas en el ámbito de la Ciencia de la Información: el paradigma de Análisis de Dominio (AD), también denominada Teórica Analítica de Dominio, que constituye uno de los sustentos epistémicos adoptados para el desarrollo de un proyecto de investigación realizado en el Departamento de Bibliotecología de la Universidad Nacional de Misiones. Empleando como metodología la revisión teórica, se abordarán los fundamentos que originaron dicha propuesta, así como los antecedentes latentes y emergentes en indagaciones y trabajos previos a la formulación de su principal exponente, Birger Hjørland. Además, se analizará el alcance semántico de la expresión, las posibilidades teóricas que el análisis de dominio posee para el desarrollo y el afianzamiento de la investigación bibliotecológica, así como las aproximaciones metodológicas e implicaciones prácticas que su creador enuncia. Se concluye que el análisis de dominio permite reconocer los conceptos relevantes de un dominio dentro de la Ciencia de la Información, sus relaciones jerárquicas y vinculaciones semánticas con otros campos, al tiempo que permite el desarrollo de nuevas líneas investigativas y profundizar diversos aspectos teóricos de la Bibliotecología y la Ciencia de la Información.

ABSTRACT This article aims to present a theoretical framework that emerged in the last decades on the Information Science sphere: Domain-analysis --also referred as Domain-analytic theory--, which comprises one of the epistemic basis implemented as part of the development of a research project conceived on the Department of Library Science of the Universidad Nacional de Misiones. Using theoretical review as methodology, the foundations that originated the proposal will be addressed, as well as the latent and emerging antecedents in inquiries and work prior to the formulation of its main exponent, Birger Hjørland. On the other hand, the semantic scope of the expression will be analyzed, in addition to the theoretical possibilities that Domain-analysis has towards the expansion and strengthening of metatheory in library science research, as well as the methodological approaches and practical matters, both issues described by its creator. It is concluded that Domain-analysis allows recognizing relevant concepts of a domain within Information Science, its hierarchical relationships and semantic links with other fields, while allowing the development of new research lines and deepen various theoretical aspects of Library and Information Science.

Application of heart rate variability in acupuncture research / 针刺研究

The measurement of heart rate variability (HRV) has the advantages of noninvasiveness and simple operation and is widely used in clinical trials and scientific research for assessing reactions of the autonomic nervous system. More and more studies on acupuncture also take HRV as an important index. In addition to the definition, origin, analytical methods, and significance of time domain and frequency domain parameters of HRV, we reviewed the situations of application of HRV to acupuncture research in recent years, analyzed the influence of acupuncture and sham acupuncture, different acupuncture methods, and different acupoints on HRV, and confirmed the role of HRV in reflecting the effect of acupuncture on the vagal and sympathetic systems. However, various interference factors for HRV measurement and diverse methods for data analysis may lead to great differences in the experimental results of HRV and the interpretation of parameters. Therefore, careful analysis is needed in future studies on acupuncture with HRV as an observation index.

Research on Automatic Identification System of Traditional Chinese Medicine Constitution Based on Pulse Wave / 世界科学技术-中医药现代化

This study was aimed to explore the feasibility of identification of traditional Chinese medicine (TCM) constitution based on photoplethysmography (PPG) frequency domain analysis,and to establish an automatic identification system (AIS) of TCM constitution with simple operation and good generalization.The Classification and Determination of Constitution in TCM was used to evaluate the subjects' constitutional state.Pulse wave sensor was used to collect the pulse wave signal.Spectral characteristics were analyzed by power spectrum analysis.Eight classification algorithms of data mining were used to establish the model of qi-insufficiency constitution.The results showed that the pulse wave harmonic peak was that qi-insufficiency constitution was higher than health group;the model was optimal when random forest algorithm was used;and the accuracy of 10-CV test was 80.4％.Sensitivity reached 73.2％.Specificity and receiver operator characteristic were all above 0.8.The model has certain reliability.It was concluded that it was feasible to identify qiinsufficiency constitution by means of frequency domain analysis of PPG.It provides preliminary work for the construction of AIS of TCM constitution as well as a simple and quick assistant tool for the constitution identification of subhealth group in family health care.

Auditoría de información y auditoría de conocimiento: acercamiento a su visualización como dominios científicos / Information audit and knowledge audit: an approach to their visualization as scientific domains

OBJETIVO: realizar un acercamiento a la visualización de los dominios auditorías de información y auditorías de conocimiento, a partir del análisis de la producción científica de las bases de datos LISA, Scopus y Web of Knowledge, entre los años 1994 al 2013. MÉTODOS: se utilizaron métodos bibliométricos y técnicas de visualización basadas en el análisis de redes sociales para analizar y procesar los datos; el análisis-síntesis para conformar la base teórica y metodológica, así como el sistémico-estructural para abordar las relaciones entre auditorías de información y auditorías de conocimiento, con un enfoque integral. RESULTADOS: se determinó la productividad por años, los autores más productivos, la colaboración científica, las publicaciones más productivas, la tipología documental y las temáticas más citadas. Para auditoría de información fueron 12 los autores más productivos y los países líderes fueron Estados Unidos, Gran Bretaña, China y España. Para auditoría del conocimiento resultaron 4 autores como los más productivos y como países líderes estuvieron China, Reino Unido, Estados Unidos, Bulgaria y Australia. CONCLUSIONES: en las publicaciones sobre auditoría del conocimiento se observa una tendencia al incremento en los próximos años y, a diferencia de las auditorías de información, se han orientado más hacia las áreas temáticas de las ciencias de la computación y las ciencias empresariales

OBJECTIVE: approach the visualization of the domains information audit and knowledge audit by analyzing the scientific production contained in the databases LISA, Scopus and Web of Knowledge from 1994 to 2013. METHODS: bibliometric methods and visualization techniques were used, based on the analysis of social networks to examine and process the data. The analysis-synthesis method was used to build to a theoretical and methodological base, whereas the structural-systemic method was used to approach the relationships between information audit and knowledge audit in a comprehensive manner. RESULTS: determination was made of the productivity per year, the most productive authors, scientific cooperation, the most productive publications, the document typology and the most cited topics. The information audit found 12 most productive authors. The leading countries were the United Stated, the United Kingdom, China and Spain. The knowledge audit found 4 most productive authors, and the leading countries were China, the United Kingdom, the United States, Bulgaria and Australia. CONCLUSIONS: publications on knowledge audit show a tendency to increase in number in the years to come, and unlike information audits, they are more oriented to theme areas related to computer and enterprise sciences

El enfoque bibliométrico para la identificación de paradigmas en dominios de conocimiento / The bibliometric approach to identify paradigms in knowledge domains

El presente trabajo es un breve acercamiento a la bibliometría como enfoque para la identificación de paradigmas en dominios de conocimiento. Se analizan los resultados de la aplicación directa de la bibliometría durante los últimos 45 años para estudiar la estructura cognoscitiva y social de la ciencia, así como contribuir a su historia intelectual. Se aborda la perspectiva del análisis de citas, y en particular los procesos de agrupación de co-citaciones, para la identificación de frentes de investigación y paradigmas emergentes. Se reconocen las dos visiones antagónicas en torno al uso del análisis de citación como técnica para el examen de la investigación científica: la crítica constructivista y la teoría normativa. Se asume la teoría normativa para reconocer el potencial de la bibliometría como enfoque, herramienta o método para el análisis de un dominio de conocimiento. Se enuncia la importancia de su integración con los enfoques histórico y epistemológico para la identificación de transformaciones paradigmáticas en la actividad científica.

The current paper is a brief approximation to Bibliometrics as approach for the identification of paradigms in knowledge domains. It is analyzed the use of Bibliometrics for the study of cognoscitive and social structure of Science, as well as its intellectual history during the last 45 years. The article deals with perspectives based on citation analysis, and particularly processes of co-citation clustering, for the identification of research fronts and emergent paradigms. It is recognized two antagonic visions related to the use of citation analysis as technique for research evaluation: the constructivist critic and the normative theory. It is assumed the normative theory to identify the potential utility of Bibliometrics as approach, tool or method for the analysis of a knowledge domain. It is enunciated the importance of its integration to historical and epistemological approaches for the identification of paradigmatic transformations in the scientific activity.

Parameter identification algorithm for fault location using one terminal data based on frequency domain / 西安交通大学学报·英文版

This paper presents a novel algorithm of fault location for transmission line. Solving the network spectrum equations for different frequencies the fault can be located accurately by this algorithm with one terminal data of voltage and current, and the identified parameters, such as fault distance, fault resistance, and opposite terminal system resistance and inductance. The algorithm eliminates the influence of the opposite system impedance on the fault location accuracy, which causes the main error in traditional fault location methods using one terminal data. A method of calculating spectrum from sampled data is also proposed. EMTP simulations show the validity and higher accuracy of the fault location algorithm compared to the existing ones based on one terminal data.

Parameter identification algorithm for fault location using one terminal data based on frequency domain / 药物分析学报

This paper presents a novel algorithm of fault location for transmission line. Solving the network spectrum equations for different frequencies the fault can be located accurately by this algorithm with one terminal data of voltage and current, and the identified parameters, such as fault distance, fault resistance, and opposite terminal system resistance and inductance. The algorithm eliminates the influence of the opposite system impedance on the fault location accuracy, which causes the main error in traditional fault location methods using one terminal data. A method of calculating spectrum from sampled data is also proposed. EMTP simulations show the validity and higher accuracy of the fault location algorithm compared to the existing ones based on one terminal data.

Study on the relationship between cyclical power of radial artery motion and pulse force / 中华中医药杂志

Objective:To study the relationship between different pulse forces and cyclical power(CP)of radial artery motion.Methods:39 patients’and 20 healthy persons’ ECG and pressure sphygmograms were collected synchronously with NX-1 sphygmograph.On the basis of automatic detecting R waves of ECG and FFT analysis of pressure sphygmograms with SPTool of MATLAB 7.0.1,change in frequency domain of radial artery motion with different forces was observed and CP was worked out.Results: There is signifi cant deviation between CP of pulse tracings with different forces(pulse tracings with powerful force〉pulse tracings with normal force〉pulse tracings with weak force).Conclusion: CP of radial artery motion can be used to discriminate pulse force.

Fatigue analysis system with HR and HRV as indexes / 医疗卫生装备

In this paper,heart rate (HR) and heart rate variability (HRV) are extracted from ECG,and the five indexes in both time and frequency domains are analyzed.The result shows that the standard deviation (SDNN) of R-R intervals,the value of total power (TP),the power value of low frequency (LF) of HRV and the value of LF/HF increase obviously,while the power value of high frequency (HF) decreases markedly after fatigue.The physical fatigue level is classified according to the rate of increase and decrease of the indexes above.It is suggested that these five ECG indexes be used to reflect and evaluate the degree of physical fatigue quantitatively.

Analysis of Heart Rate Variability in Preoperative Diabetic Patients by Linear and Nonlinear Dynamics / 대한마취과학회지

BACKGROUND: The aim of this study was to investigate the underlying changes in heart rate variability (HRV) of preoperative diabetic patients using five analytical methods; SDNN (standard deviation of normal to normal intervals), SDANN (standard deviation of the mean of normal RR intervals for each 5 min period of the entire electrocardiographic recording), RMSSD (root mean square successive difference, the squre root of the mean of the sum of the squares of differences between adjacent normal RR intervals over the entire electrocardiographic recording), PNN50 (percent of difference between adjacent normal RR intervals that are greater than 50 ms computed over the entire electrocardiographic recording) for linear time domain analysis and approximate entropy for nonlinear complexity analysis. METHODS: HRV values analyzed by five different measures were compared between a control group of ten nondiabetics without any significant systemic disease and a diabetic group of ten patients from the preoperative ambulatory electrocardiographic recordings. RESULTS: Approximate entropy, SDNN and SDANN values were significantly lower in the diabetic group than those of the control group (P< 0.01). CONCLUSIONS: Significantly decreased approximate entropy, SDNN and SDANN could provide information about decreased cardiovascular complexity and sympathetic output, suggesting the nature of dysfunction of the diabetic cardiovascular system.

Linear and Nonlinear Analysis of Heart Rate Variability in Postoperative Myocardial Ischemic Patients: Time Domain Analysis versus Approximate Entropy / 대한마취과학회지

BACKGROUND: Postoperative myocardial ischemia has been regarded as one of the major predictors of adverse cardiac outcomes after noncardiac surgery in high risk patients. Many schemes have been proposed to stratify the potential risk of this patient group in more noninvasive and cost-effective ways and analysis of heart rate variability (HRV) is one of them. To uncover the underlying changes in HRV with postoperative myocardial ischemia five analytical methods were introduced; SDNN (standard deviation of normal to normal intervals), SDANN (standard deviation of the mean of normal RR intervals for each 5 min period of the entire electrocardiographic recording), RMSSD (root mean square successive difference, the squre root of the mean of the sum of the squares of differences between adjacent normal RR intervals over the entire electrocardiographic recording), PNN50 (percent of difference between adjacent normal RR intervals that are greater than 50 ms computed over the entire electrocardiographic recording) for linear time domain analysis and approximate entropy for nonlinear complexity analysis. METHODS: Sixteen vascular surgical patients were monitored by an ambulatory electrocardiogram preoperatively and during the first postoperative day (POD1). HRV values analyzed by five different measures were compared between a control group (C group) of eight patients with no postoperative ischemia and a postoperative ischemic group (PI group) of eight with ischemia on POD1. RESULTS: Approximate entropy was the only measure of HRV which was significantly lower in PI group than that of C group (P< 0.01) on POD1. CONCLUSIONS: Approximate entropy, a complexity measure could provide more sensitive information about the physiologic changes associated with postoperative ischemia which could not be obtained from the conventional HRV measures. Time domain analyses can be used as adjuvant measures providing information about the cardiac autonomic regulation.

Signal Averaged Electrocardiography Using Holter Tape in Patients without Heart Disease

BACKGROUND: Ventrlcular tachyarrhythmias are major cause of sudden cardiac death in patients after myocardial infarction and their accurate detection seems to be important in prevention of sudden cardiac death. Clinical findings, treasmill test, holter monitoring and coronary angiography have been used to search for high risk group in sudden cardiac death. Recently electrographysiologic stimulation has been to this, but it is not practical, because of high cost and invasiveness. Signal averaged electrocardiogram(SAECG) may be helpful in prediction of high risk group in sudden cardiac death. So we try to know the values of SAECG in Korean patients without heart disease. RESULTS: 1) The mean value and standard deviation of Time domain analysis is as follows ; fQRS : 106.8+/-12.3ms, RMS : 36.2+/-21.5(micro)V, LAS : 27.2+/-8.1ms. 2) The mean value and standard deviation of Spectral turbulence analysis is a follows ; LSCR : 58.6+/-3.9, ISCM : 95.2+/-0.8, ISCSD : 71.8+/-15.7, SE : 6.9+/-1.8. CONCLUSION: There was no significant difference between male and female. Time domain analysis shows significant differences among each hour but spectral turbulence analysis did not. Spectral turbulence analysis shows high specificity.

Comparative Study of Signal-Averaged Electrocardiogram between Time Domain Analysis and Spectral Turbulence Analysis by 24-hr Holter Monitoring / 대한내과학회지

OBJECTIVES: Signal-averaged electrocardiography (SAECG) has been found to be a useful noninvasive technique for identifying patients at risk for life-threatening ventricular tachycardia. Delayed and fragmented activation of abnormal myocardial tissues causes the occurrence of high frequency low amplitude (HFLA) electocardiographic signals or late potentials. Generally, there are two methods in analyzing signal-averaged electrocardiography. Late potentials in the time domain analysis do not provide sufficient diagnostic power with regard to life-threatening Ventricular tachycardia. Buckingham et al. (1989) reported a time-domain sensitivity of 62%, a specificity of 75%. Spectral turbulence analysis (STA) of the signal-averaged ECG is the most recent frequency domain technique to improve the time domain sensitivity and specificity. So, We designed the study to compare the efficacy of Time Domain Analysis and Spectral Turbulence Analysis among five groups (Normal control, QRS widening, Postmyocardial infarction, Frequent VPC's with group beats, Nonsustained ventricular tachycardia). METHODS: 88 patients were selected from the patients who had been admitted between January 1994 and October l994, at National Medical Center. Patients were divided into five groups, which were respectively, Group A: Normal control group (n=33), Group B: QRS widening group (n=14), Group C: Postmyocardial infarction group (n=10), Group D: Frequent VPC's with group beats (n=22), Group E: Nonsustained VT group (n=9). We compared Spectral Turbulence Analysis and Time Domain Analysis of Signal-Averaged Electrocardiogram by 24 hours-Holter monitoring. RESULTS: 1) In normal control group(Group A), 9.1%(3 patients) were positive by Time Domain Analysis, but, all were negative by Spectral Turbulence Analysis. 2) In QRS widening group (Group B), 71.4%(10 patients) were positive by Time Domain Analysis, but, all were negative by Spectral Turbulence Analysis. 3) In postmyocardial infarction group (Group C), 309o were positive by Time Domain Analysis, and 10% were positive by Spectral Turbulence Analysis. 4) In frequent VPC's group (Group D), 22.7% (5 patients) were positive by Time Domain Analysis, and, 4.5%(1 patient) was positive by Spectral Tur-bulence Analysis. 5) In Nonsustained VT group (Group E), 33.3% (3 patients) were positive by Time Domain Analysis, and 11.1% (1 patient) was positive by Spectral Turbulence Analysis. CONCLUSIONS: In Time Domain Analysis, abnormal results were presented at Group R (QRS widening group) by 71.4%, which was markedly higher than other groups. But, in Spectral Turbulence Analysis, abnormal results were not presented at Group A and Group B. In Group A and Group B, Spectral Turbulence Analysis shows less false positive results than Time Domain Analysis.

Comparison between Myocardial Infarction and Congestive Heart Failure Using by Heart Rate Variability Analysis of 24 hours Holter Monitoring

OBJECTIVES: Power spectrum analysis decomposes the heart rate signal into its frequency components and facilitates separation of sympathetic (low frequency) and parasympathetic (high frequency) activity. In congestive heart failure, augmented sympathetic tone and decreased parasympathetic tone were found. Autonomic nervous system was normalized 6 months after myocardial infarction. So we compared the autonomic nervous system activity by the heart rate variability in congestive heart failure and old myocardial infarction. METHODS: The protocol involved 20 healthy subjects (Group 1), 5 congestive heart failure patients not caused by myocardial infarction (Group 2), 4 congestive heart failure patients due to myocardial infarction and 11 old myocardial infarction patients without heart failure. We took 24 hour Holter monitoring by Del Mar Avionic tape recorder. All Holter tapes were analyzed with use of Model 563 Stratascan Holter Analysis System. We computed power spectra on each 256 sec segment of each hour during 24 hour recording. So, RR interval, SD of RR interval by time domain, and LF, HF, LF/HF ratio, Total PSD by frequency domain were measured. RESULTS: In congestive heart failure, nocturnal HF peak and diurnal variation of LF/HF ratio was decreased relative to healthy subjects. Nocturnal HF peak in old myocardial infarction was not visualized. All of LF, HF and Total PSD in congestive heart failure and old myocardial infarction patients relative to healthy subjects. CONCLUSION: On heart rate variability analysis using by 24 hour Holter monitoring, abnormal autonomic nervous activity was demonstrated in congestive heart failure and old myocardial infarction patients relative to healthy subjects.

Study on the interrelationship between time domain analysis of heart rate variability and chronic renal failure / 第二军医大学学报

Objective: To assess the autonomic nervous impairment in chronic renal failure and its related factors. Methods: Forty adults were randomly selected including in patients in the nephrology ward and healthy subjects for routine medical examination. The subjects were classified into 4 groups: normal subjects(NS),normal renal function,nitremia, uremic patients. The time domain measurements of heart rate variability(HRV) and ambulatory blood pressure were analyzed simultaneously . Results: (1) There were significant differences as compared with normal subjects in the time domain measurements of HRV in uremic group. It decreased significantly when the patient was defined as end stage chronic renal failure. There were no significant differences between NS,normal renal function group and nitremic group. (2) Time domain measurements of HRV was significantly lower( P