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1.
J Pediatr ; 232: 147-153.e1, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33421423

RESUMO

OBJECTIVE: Current estimates of the incidence of tachyarrhythmias in infants rely on clinical documentation and may not reflect the true rate in the general population. Our aim was to describe the epidemiology of tachyarrhythmia detected in a large cohort of infants using direct-to-consumer heart rate (HR) monitoring. STUDY DESIGN: Data were collected from Owlet Smart Sock devices used in infants in the US with birthdates between February 2017 and February 2019. We queried the HR data for episodes of tachyarrhythmia (HR of ≥240 bpm for >60 seconds). RESULTS: The study included 100 949 infants (50.8% male) monitored for more than 200 million total hours. We identified 5070 episodes of tachyarrhythmia in 2508 infants. The cumulative incidence of tachyarrhythmia in our cohort was 2.5% over the first year of life. The median age at the time of the first episode of tachyarrhythmia was 36 days (range, 1-358 days). Tachyarrhythmia was more common in infants with congenital heart disease (4.0% vs 2.4%; P = .015) and in females (2.7% vs 2.0%; P < .001). The median length of an episode was 7.3 minutes (range, 60 seconds to 5.4 hours) and the probability of an episode lasting longer than 45 minutes was 16.8% (95% CI, 15.4%-18.3%). CONCLUSIONS: We found the cumulative incidence of tachyarrhythmia among infants using direct-to-consumer HR monitors to be higher than previously reported in studies relying on clinical diagnosis. This finding may represent previously undetected subclinical disease in young infants, the significance of which remains uncertain. Clinicians should be prepared to discuss these events with parents.


Assuntos
Triagem e Testes Direto ao Consumidor , Determinação da Frequência Cardíaca/instrumentação , Monitorização Ambulatorial/instrumentação , Taquicardia/diagnóstico , Triagem e Testes Direto ao Consumidor/métodos , Feminino , Determinação da Frequência Cardíaca/métodos , Humanos , Incidência , Lactente , Masculino , Monitorização Ambulatorial/métodos , Estudos Prospectivos , Taquicardia/epidemiologia , Estados Unidos/epidemiologia
2.
J Pediatr ; 221: 88-92.e1, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32222255

RESUMO

OBJECTIVE: To compare 2 different methods (auscultation with a stethoscope and umbilical cord palpation) of heart rate (HR) estimation in newborns at risk for resuscitation in a low-resource setting. STUDY DESIGN: Sixty newborns at risk for resuscitation born at the St. Luke Catholic Hospital in Wolisso (Ethiopia) were randomized to HR assessment by auscultation using a stethoscope or umbilical cord palpation. HR was assessed at 60, 90, 120 seconds, and 5 minutes of life. The primary outcome was the agreement of HR obtained by auscultation or palpation compared with the HR determined by electrocardiogram. RESULTS: Mean difference between auscultation using a stethoscope and electrocardiogram was -13 bpm, -4 bpm, -6 bpm, and -10 bpm at 60, 90, 120 seconds, and at 5 minutes of life. Mean difference between palpation and electrocardiogram of was -20 bpm, -25 bpm, -23 bpm, and -31 bpm at 60, 90, 120 seconds, and at 5 minutes of life. The magnitude of the difference between auscultation and electrocardiogram was lower than that between palpation and electrocardiogram over time (P = .007). HR range was correctly identified in 14 out of 16 measurements (87%) with HR <100 bpm. CONCLUSION: HR assessment by auscultation was more accurate compared with cord palpation, but both may provide adequate clinical information to healthcare providers in terms of HR ranges. The clinical advantage of providing a stethoscope in low-resource settings remains to be established. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03854435.


Assuntos
Auscultação , Eletrocardiografia , Determinação da Frequência Cardíaca/métodos , Palpação , Ressuscitação , Etiópia , Feminino , Recursos em Saúde , Humanos , Recém-Nascido , Masculino , Medição de Risco
3.
Prensa méd. argent ; 105(9 especial): 644-651, oct 2019. fig
Artigo em Inglês | LILACS, BINACIS | ID: biblio-1046879

RESUMO

The article introduces the findings of the analysis of the existing approaches to the development of mathematical models of acoustic heart phenomena. The analysis of mathematical methods that can be used to model heart sounds has been performed with the use of reference signals from the 3M Open Library (Littmann Library) and a set of signals obtained by the authors during their previous scientific efforts. The analysis findings have allowed revealing the approaches and methods that are most suitable for developing the mathematical models of human phonocardiograms (normal and pathological) for further research efforts meant to develop methods to single out heart beats against the high level of interference and creating intervalograms to characterize the heart rate at the current moments of time. In addition to the generation of model phonocardiograms, the article reviews the methods to analyze model and real-life phonocardiograms with the assessment of an input from random and deterministic components.


Assuntos
Humanos , Fonocardiografia/instrumentação , Análise Espectral , Acústica , Modelos Estatísticos , Determinação da Frequência Cardíaca/métodos , Coração/fisiologia
4.
Sensors (Basel) ; 19(13)2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31284380

RESUMO

In this paper, we report the development of a portable energy-efficient interrogator (Perrogator) for wavelength-based optical sensors. The interrogator is based on a compact solution encompassing a white light source and the spectral convolution between the sensor and a tunable filter, which is acquired by a photodetector, where a microcontroller has two functions: (i) To control the filter tuning and to (ii) acquire the photodetector signal. Then, the data is sent to a single-board computer for further signal processing. Furthermore, the employed single-board computer has a Wi-Fi module, which can be used to send the sensors data to the cloud. The proposed approach resulted in an interrogator with a resolution as high as 3.82 pm (for 15.64 nm sweeping range) and maximum acquisition frequency of about 210 Hz (with lower resolution ~15.30 pm). Perrogator was compared with a commercial fiber Bragg grating (FBG) interrogator for strain measurements and good agreement between both devices was found (1.226 pm/µÎµ for the commercial interrogator and 1.201 pm/µÎµ for the proposed approach with root mean square error of 0.0144 and 0.0153, respectively), where the Perrogator has the additional advantages of lower cost, higher portability and lower energy consumption. In order to demonstrate such advantages in conjunction with the high acquisition frequency allowed us to demonstrate two wearable applications using the proposed interrogation device over FBG and Fabry-Perot interferometer (FPI) sensors. In the first application, an FBG-embedded smart textile for knee angle assessment was used to analyze the gait of a healthy person. Due to the capability of reconstructing the FBG spectra, it was possible to employ a technique based on the FBG wavelength shift and reflectivity to decouple the effects of the bending angle and axial strain on the FBG response. The measurement of the knee angle as well as the estimation of the angular and axial displacements on the grating that can be correlated to the variations of the knee center of rotation were performed. In the second application, a FPI was embedded in a chest band for simultaneous measurement of breath and heart rates, where good agreement (error below 5%) was found with the reference sensors in all analyzed cases.


Assuntos
Marcha/fisiologia , Determinação da Frequência Cardíaca/instrumentação , Articulação do Joelho/fisiologia , Processamento de Sinais Assistido por Computador , Dispositivos Eletrônicos Vestíveis , Desenho de Equipamento , Tecnologia de Fibra Óptica/instrumentação , Frequência Cardíaca/fisiologia , Determinação da Frequência Cardíaca/métodos , Humanos , Interferometria/instrumentação , Respiração , Tecnologia sem Fio/instrumentação
5.
Lancet Glob Health ; 7(3): e347-e356, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30784635

RESUMO

BACKGROUND: In 2015, an estimated 303 000 women died in pregnancy and childbirth. Obstetric haemorrhage, sepsis, and hypertensive disorders of pregnancy account for more than 50% of maternal deaths worldwide. There are effective treatments for these pregnancy complications, but they require early detection by measurement of vital signs and timely administration to save lives. The primary aim of this trial was to determine whether implementation of the CRADLE Vital Sign Alert and an education package into community and facility maternity care in low-resource settings could reduce a composite of all-cause maternal mortality or major morbidity (eclampsia and hysterectomy). METHODS: We did a pragmatic, stepped-wedge, cluster-randomised controlled trial in ten clusters across Africa, India, and Haiti, introducing the device into routine maternity care. Each cluster contained at least one secondary or tertiary hospital and their main referral facilities. Clusters crossed over from existing routine care to the CRADLE intervention in one of nine steps at 2-monthly intervals, with CRADLE devices replacing existing equipment at the randomly allocated timepoint. A computer-generated randomly allocated sequence determined the order in which the clusters received the intervention. Because of the nature of the intervention, this trial was not masked. Data were gathered monthly, with 20 time periods of 1 month. The primary composite outcome was at least one of eclampsia, emergency hysterectomy, and maternal death. This study is registered with the ISRCTN registry, number ISRCTN41244132. FINDINGS: Between April 1, 2016, and Nov 30, 2017, among 536 223 deliveries, the primary outcome occurred in 4067 women, with 998 maternal deaths, 2692 eclampsia cases, and 681 hysterectomies. There was an 8% decrease in the primary outcome from 79·4 per 10 000 deliveries pre-intervention to 72·8 per 10 000 deliveries post-intervention (odds ratio [OR] 0·92, 95% CI 0·86-0·97; p=0·0056). After planned adjustments for variation in event rates between and within clusters over time, the unexpected degree of variability meant we were unable to judge the benefit or harms of the intervention (OR 1·22, 95% CI 0·73-2·06; p=0·45). INTERPRETATION: There was an absolute 8% reduction in primary outcome during the trial, with no change in resources or staffing, but this reduction could not be directly attributed to the intervention due to variability. We encountered unanticipated methodological challenges with this trial design, which can provide valuable learning for future research and inform the trial design of future international stepped-wedge trials. FUNDING: Newton Fund Global Research Programme: UK Medical Research Council; Department of Biotechnology, Ministry of Science & Technology, Government of India; and UK Department of International Development.


Assuntos
Determinação da Pressão Arterial/instrumentação , Eclampsia/epidemiologia , Pessoal de Saúde/educação , Determinação da Frequência Cardíaca/instrumentação , Histerectomia/estatística & dados numéricos , Mortalidade Materna , Complicações na Gravidez/diagnóstico , África/epidemiologia , Determinação da Pressão Arterial/métodos , Diagnóstico Precoce , Intervenção Médica Precoce , Feminino , Haiti/epidemiologia , Recursos em Saúde , Determinação da Frequência Cardíaca/métodos , Humanos , Hipertensão Induzida pela Gravidez/diagnóstico , Hipertensão Induzida pela Gravidez/terapia , Índia/epidemiologia , Serviços de Saúde Materna , Hemorragia Pós-Parto/diagnóstico , Hemorragia Pós-Parto/terapia , Gravidez , Complicações na Gravidez/terapia , Complicações Infecciosas na Gravidez/diagnóstico , Complicações Infecciosas na Gravidez/terapia , Sepse/diagnóstico , Sepse/terapia , Sinais Vitais
6.
Prensa méd. argent ; 104(7): 352-360, sep2018. tab, graf
Artigo em Espanhol | BINACIS, LILACS | ID: biblio-1051025

RESUMO

Antecedentes: Con conceptos provenientes de la teoría de sistemas dinámicos y la geometría fractal, se ha logrado caracterizar el comportamiento de la dinámica cardíaca, dando resultados objetivos y estableciendo distinciones entre estados de normalidad y enfermedad. Objetivo: Aplicar una ley matemática exponencial de la dinámica cardíaca, inscrita en el contexto de los sistemas dinámicos y la geometría fractal, para evidenciar su utilidad diagnóstica en 16 horas. Materiales y métodos: Fueron empleados 200 Holters y registros electrocardiográficos continuos, entre normales y con diferentes alteraciones cardíacas. Se simuló una secuencia de frecuencias cardíacas en 16 y 21 horas, con la cual se construyó el atractor de cada dinámica. También se calculó la dimensión fractal y la ocupación de los atractores en el espacio fractal. Se estableció el diagnóstico físico-matemático en 16 y 21 horas y la subsecuente validación estadística. Resultados: Fueron obtenidos valores en la rejilla Kp entre 44 y 198 para estados patológicos y entre 221 y 377 para estados de normalidad en 16 horas, la sensibilidad y especificidad fue del 100% y el coeficiente Kappa de 1. Conclusión: Se logró diferenciar de manera adecuada estados normales de patológicos mediante la ley exponencial aplicada en registros de 16 horas


Background: With concepts derived from dynamical systems theory and fractal geometry, it has been possible to characterize the behavior of the cardiac dynamics, giving objective results and estabishing distinctions between states of normality and disease. Objective: To apply an exponential mathematical law of cardiac dynamics, inscribed in the context of dynamical systems and fractal geometry, to demonstrate its diagnostic utility in the context of a reduction in the evaluation time, originally of 21 hours. Materials and methods: There were used 200 Holters and cotinuous electrocardiographic records, between normal and with different cardiac alterations. A sequence of heart rates was simulated in 16 and 21 hours, with which the attractor of each dynamic was constructed. There were also calculated the fractal dimension and the occupation of the attractors in the fractal space. The physical-mathematical diagnosis was establishd at 16 and 21 hours, and the staqtistical validation was performed. Results: Values obtained in the Kp grid were between 44 y 198 for pathological sttes, and between 221 and 377 for normal states in 16 hours. The sensitivity and specificity was 100% and the Kappa coefficient was 1. Conclusion: It was possible to differentiate adequately normal states of pathological by means fo the exponential law applied in registers of 16 hours


Assuntos
Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Eletrocardiografia Ambulatorial/estatística & dados numéricos , Dinâmica não Linear , Fractais , Determinação da Frequência Cardíaca/métodos , Frequência Cardíaca , Padrões de Referência
7.
Arq. bras. cardiol ; 110(4): 303-311, Apr. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-888047

RESUMO

Abstract Background: The prevalence of orthostatic hypotension (OH) increases with age and is associated with changes in autonomic regulation of blood pressure (BP) and heart rate (HR). Objective: to assess HR and HR variability (HRV) in elderly subjects with OH and determine OH predictors. Methods: a total of 105 patients aged ≥ 60 years, 39 with OH (case group) and 66 without OH (control group) (age-matched) were studied. Patients underwent clinical assessment, electrocardiogram, biochemistry tests and Holter monitoring for spectral analysis of HRV (Fourier transform) in the supine and orthostatism positions to identify low frequency (LF) and high frequency (HF) components, as well as the LF/HF ratio. Results: median age was 73.0 years, 64 patients were women. In all participants, there was a reduction in HF (133.0 versus 76.0 ms2, p = 0.001) and increase in LF/HF (1.6 vs 2.1; p < 0.001) and no change in LF (233.0 versus 218.0 ms2, p = 0.080). Between-group comparisons revealed significant differences in the median values of HR in the supine position (62.0 vs. 69.0 bpm, p = 0.001) and LF in the supine position (157.0 in case group vs. 275.0 ms2 in the control group, p = 0.014). Spearman's correlation coefficient of 0.27 was found between the groups. Multivariate analysis revealed that HR in the supine position was an independent variable for OH (p = 0.001- 95%CI = -0.022 and -0.006). Using the operating characteristic curve, the best cutoff point was 61 bpm, with a sensitivity of 77.3% and specificity of 51.3%, positive predictive value of 61.3%, and negative predictive value 69.3%. Odds ratio was 3.23 for OH in patients with a HR lower than 61 bpm. Conclusions: lower LF and HR in the supine position were found in patients with OH, regardless of age and gender. The independent predictor for OH was HR in the supine position, with an odds ratio of 3.23 for values lower than 61 bpm.


Resumo Fundamento: A prevalência de hipotensão ortostática (HO) aumenta com a idade e está relacionada a alterações da regulação autonômica da pressão arterial (PA) e da frequência cardíaca (FC). Objetivos: Avaliar a FC e variabilidade da FC (VFC) em idosos com HO e verificar os preditores de HO. Métodos: foram avaliados 105 pacientes, com idade ≥ 60 anos, 39 com HO (grupo caso) e 66 sem HO (grupo controle), pareados por idade. Foram submetidos à avaliação clínica, eletrocardiograma, exames de bioquímica e monitoramento pelo Holter para análise espectral da VFC (transformação de Fourier), na posição supina e em ortostatismo, para detectar os componentes de baixa frequência (LF), de alta frequência (HF) e sua relação LF/HF. Resultados: A mediana de idade foi de 73,0 anos, 64 dos pacientes eram mulheres. Em toda a população, com a mudança de posição, houve redução do HF (133,0 versus 76,0 ms2, p = 0,001) e aumento da relação LF/HF (1,6vs2,1; p < 0,001), sem alteração quanto à mediana do componente LF (233,0 versus 218,0 ms2, p = 0,080). Quando comparado o grupo caso ao grupo controle, houve diferença quanto às medianas da FC nas posições supina (62,0 vs 69,0 bpm, p = 0,001) e do componente LF na posição supina (157,0 no grupo caso vs 275,0 ms2 no grupo controle, p = 0,014). Quanto ao gênero, o coeficiente de Spearman foi de 0,27 entre os grupos. Pela análise multivariada, a FC na posição supina foi a variável independente para a ocorrência de HO (p = 0,001- IC95% = -0,022 e -0,006). Pela curva de operação característica, o melhor ponto de corte para FC foi de 61 bpm, com sensibilidade de 77,3%, especificidade de 51,3%, valor preditivo positivo de 61,3%, e o valor preditivo negativo de 69,3%. A razão de chance foi de 3,23 para HO entre os pacientes com FC < 61 bpm. Conclusões: Houve menor valor do LF e da FC na posição supina entre os pacientes com HO, sem influência da idade e do gênero. O preditor independente para HO foi a FC na posição supina, a qual apresentou uma razão de chance de 3,23 se inferior a 61 bpm.


Assuntos
Humanos , Masculino , Feminino , Idoso , Frequência Cardíaca/fisiologia , Hipotensão Ortostática/fisiopatologia , Valores de Referência , Fatores de Tempo , Pressão Sanguínea/fisiologia , Métodos Epidemiológicos , Fatores Etários , Decúbito Dorsal/fisiologia , Eletrocardiografia , Posicionamento do Paciente , Determinação da Frequência Cardíaca/métodos
8.
Arq Bras Cardiol ; 110(4): 303-311, 2018 Apr.
Artigo em Inglês, Português | MEDLINE | ID: mdl-29561965

RESUMO

BACKGROUND: The prevalence of orthostatic hypotension (OH) increases with age and is associated with changes in autonomic regulation of blood pressure (BP) and heart rate (HR). OBJECTIVE: to assess HR and HR variability (HRV) in elderly subjects with OH and determine OH predictors. METHODS: a total of 105 patients aged ≥ 60 years, 39 with OH (case group) and 66 without OH (control group) (age-matched) were studied. Patients underwent clinical assessment, electrocardiogram, biochemistry tests and Holter monitoring for spectral analysis of HRV (Fourier transform) in the supine and orthostatism positions to identify low frequency (LF) and high frequency (HF) components, as well as the LF/HF ratio. RESULTS: median age was 73.0 years, 64 patients were women. In all participants, there was a reduction in HF (133.0 versus 76.0 ms2, p = 0.001) and increase in LF/HF (1.6 vs 2.1; p < 0.001) and no change in LF (233.0 versus 218.0 ms2, p = 0.080). Between-group comparisons revealed significant differences in the median values of HR in the supine position (62.0 vs. 69.0 bpm, p = 0.001) and LF in the supine position (157.0 in case group vs. 275.0 ms2 in the control group, p = 0.014). Spearman's correlation coefficient of 0.27 was found between the groups. Multivariate analysis revealed that HR in the supine position was an independent variable for OH (p = 0.001- 95%CI = -0.022 and -0.006). Using the operating characteristic curve, the best cutoff point was 61 bpm, with a sensitivity of 77.3% and specificity of 51.3%, positive predictive value of 61.3%, and negative predictive value 69.3%. Odds ratio was 3.23 for OH in patients with a HR lower than 61 bpm. CONCLUSIONS: lower LF and HR in the supine position were found in patients with OH, regardless of age and gender. The independent predictor for OH was HR in the supine position, with an odds ratio of 3.23 for values lower than 61 bpm.


Assuntos
Frequência Cardíaca/fisiologia , Hipotensão Ortostática/fisiopatologia , Fatores Etários , Idoso , Pressão Sanguínea/fisiologia , Eletrocardiografia , Métodos Epidemiológicos , Feminino , Determinação da Frequência Cardíaca/métodos , Humanos , Masculino , Posicionamento do Paciente , Valores de Referência , Decúbito Dorsal/fisiologia , Fatores de Tempo
9.
Rev. cuba. inform. méd ; 9(1)ene.-jun. 2017.
Artigo em Inglês | LILACS, CUMED | ID: biblio-844921

RESUMO

Approximately 30 indices have been proposed for assessing heart rate variability (HRV). Some are mathematically identical or very closely related to each other, and results can be interpreted from completely different viewpoints. Comparing various indices from a tachogram, and combining statistical significance with physiological plausibility could improve the result's interpretation. Using the KubiosHRV package, we studied the chi-meditation R-R database available at Physionet.org, addressing the following questions: i) Which HRV indices are the most suitable for describing meditation effects? ii) Are the effects of meditation beneficial, harmful or insubstantial? iii) Which are the most likely physiological events associated to meditation? It was concluded that power spectrum low frequency component (LF), LF/HF ratio, and nonlinear indices α 1 and α 2, recurrence rate and Shannon entropy performed the best (p<0.05). Observed changes suggest that they harmonize with changes observed in other health-pursuing circumstances as physical training, stress combating; whereas they are in the opposite tendency of changes associated to aging, heavy smoking, high blood glucose levels, autonomic heart denervation and congestive heart failure. Changes induced by chi meditation seem to be associated to increases in respiratory component around0.04 Hz, lower entropy and reduced long-term correlation with higher cardio vascular complexity(AU)


Alrededor de 30 índices han sido propuestos para evaluar la Variabilidad de la Frecuencia Cardiaca. Algunos de esos índices son matemáticamente idénticos o muy semejantes a otros y los resultados pueden ser interpretados desde puntos de vista completamente distintos. Al comparar varios índices estimados a partir de un tacograma y combinando la significación estadística con la plausibilidad biológica pudiera mejorarse la interpretación de los resultados. Utilizando el paquete de análisis KubiosHRV estudiamos la base de datos de señales R-R Chi meditation, disponible en el portal Physionet.org, centrándonos en las interrogantes siguientes: i) ¿cuáles índices son los más adecuados para describir los efectos de la meditación? ii) ¿son los efectos de la meditación beneficiosos, nocivos o insustanciales? iii) ¿cuáles son los eventos fisiológicos asociados a la meditación? Se concluye que el componente de baja frecuencia del espectro de potencia (LF), la relación LF/HF y los índices no lineales α 1 yα 2, la razón de recurrencia y la entropía de Shannon, fueron los indicadores más apropiados (p < 0.05). Los cambios observados parecen armonizar con cambios observados en otras acciones promotoras de salud como entrenamiento físico, combatir el estrés, mientras que exhiben una tendencia opuesta a los cambios asociados al envejecimiento, hábito de fumar, elevados niveles de glucosa, denervación cardiaca, e insuficiencia cardiaca congestiva. Los cambios inducidos por la meditación chi parecen estar asociados a incrementos en el componente respiratorio próximo a los 0.04 hertzios, a una menor entropía y una menor correlación a largo término combinadas a una mayor complejidad cardiovascular(AU)


Assuntos
Humanos , Masculino , Feminino , Meditação/métodos , Determinação da Frequência Cardíaca/métodos
10.
Univ. med ; 58(1)2017. ilus, tab
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-996078

RESUMO

Introducción: la dinámica cardiaca se ha evaluado desde teorías físico' matemáticas como la probabilidad y los sistemas dinámicos, lo que ha permitido desarrollar diagnósticos y predicciones de aplicación clínica. Objetivo: medir la probabilidad de distribuciones de frecuencias cardiacas (FC) neonatales normales, para hacer una caracterización matemática, objetiva y reproducible. Metodología: se analizaron diez dinámicas normales mediante registros continuos y holters, tomando los máximos y mínimos de FC por hora durante 21 horas. Se generaron rangos de 5 latmin, y se estableció cuántas frecuencias pertenecen a cada rango. Se analizaron las distribuciones obtenidas en el espacio de probabilidades para las frecuencias cardiacas, en busca de características matemáticas de normalidad para la dinámica cardiaca neonatal. Resultados: las probabilidades de los rangos evaluados variaron entre 0,02272 y 0,2826-, y en tres de los rangos, todas las dinámicas presentaron probabilidad mínima o cero. Conclusiones: se desarrolló una caracterización general de la dinámica cardiaca neonatal normal, objetiva y reproducible.


Background: Cardiac dynamics have been evaluated from physicah mathematical theories like probability and dynamícal Systems, allowing to developing diagnosis and dinical application predictions. Objective: To measure the probability of normal neonatal heart rates distribution, for doing a mathematical characterization, objective and reproducible. Methods: It have been analyzed 10 normal dynamics through continuous records and holters, taking máximum and mínimum valúes of heart rates per hour during 21 hours. Ranges of 5 beats/min were generated; obtained distributions in probability space for heart rates were analyzed, to search normality mathematical characteristics for neonatal cardiac dynamics. Results: The probabilities of the evaluated ranges varied between 0.02272 and 0.2826; also, in three of the ranges, all the dynamics showed a minimum probability or zero. Condusions: A general characterization, objective and reproductible, of normal neonatal cardiac dynamics, was developed.


Assuntos
Teoria da Probabilidade , Determinação da Frequência Cardíaca/métodos
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