Variabilidad de la señal de frecuencia de pulso obtenida mediante pulsioximetría nocturna en pacientes con síndrome de apnea hipopnea del sueño / Variability of pulse signal frequency obtained using nocturnal pulse oximetry in patients with sleep apnoea/hypoapnoea syndrome

IntroducciónLa medida de tendencia central (MTC) es una técnica de análisis no lineal que aplicada a diagramas de diferencias de segundo orden permiten cuantificar el grado de variabilidad de una serie de datos. En el presente estudio, se pretende cuantificar y caracterizar las modificaciones de la frecuencia cardiaca obtenidas por pulsioximetría en pacientes con sospecha clínica de síndrome de apnea hipopnea del sueño (SAHS) mediante la utilización de la MTC y valorar su utilidad diagnóstica.Pacientes y métodosSe incluyen en el estudio 187 pacientes, realizándose un estudio polisomnográfico y pulsioximétrico nocturno. Para la valoración de la variabilidad de la frecuencia cardiaca, se utilizó la MTC aplicada a gráficos de diferencias de segundo orden obtenidos del registro de la frecuencia cardiaca.ResultadosLos pacientes con SAHS presentaron una mayor variabilidad de la frecuencia cardiaca que los pacientes sin SAHS (0,449 vs. 0,666, p<0,001. En el análisis multivariante, la frecuencia cardiaca, la saturación mínima y el índice de desaturación del 4% presentaron una relación independiente con la variabilidad de la frecuencia cardiaca. Como método diagnóstico, la MTC de la frecuencia cardiaca proporcionó una sensibilidad de 69,3%, una especificidad de 77,6% y una precisión diagnóstica de 72,7%ConclusionesLos pacientes con SAHS presentan durante la noche una mayor variabilidad de la frecuencia cardiaca, valorada mediante la aplicación de la medida de tendencia central a diagramas de diferencias de segundo orden de la frecuencia cardiaca. Como método de despistaje, la MTC aplicada a la frecuencia cardiaca presentan una sensibilidad y especificidad moderada(AU)

IntroductionThe measurement of central tendency (MCT) is a non-linear analysis technique which applied to second order differences diagrams enables the degree of variability to be quantified in a data series. In the present study an attempt is made to quantify and characterise the changes in heart rate obtained by pulse oximetry in patients with a clinical suspicion of sleep apnoea/hypoapnoea syndrome (SAHS) using the MCT and to evaluate its diagnostic use.Patients and MethodsA total of 187 patients were included in the study, on whom a nocturnal polysomnographic and pulse oximetry study was performed. To evaluate the variability of the heart rate the MCT applied to graphs of second order differences obtained from the heart rate record.ResultPatients with SAHS had a higher heart rate variablity than patients without SAHS (0.449 vs. 0.666, P<0.001. In the multivariate analysis, the heart rate, the minimum saturation and the desaturation index of 4% were independently associated with the heart rate variability. As a diagnostic method, the MCT of the heart rate gives a sensitivity of 69.3%, a specificity of 77.6% and a diagnostic precision of 72.7%ConclusionsPatients with SAHS have a greater variabilityin heart rate during the night, evaluated by applying the MCT of the heart rate to diagrams of second order differences. As a screening method, the MCT applied to the heart rate has a moderate sensitivity and specificity(AU)

[Variability of pulse signal frequency obtained using nocturnal pulse oximetry in patients with sleep apnoea/hypoapnoea syndrome]. / Variabilidad de la señal de frecuencia de pulso obtenida mediante pulsioximetría nocturna en pacientes con síndrome de apnea hipopnea del sueño.

INTRODUCTION: The measurement of central tendency (MCT) is a non-linear analysis technique which applied to second order differences diagrams enables the degree of variability to be quantified in a data series. In the present study an attempt is made to quantify and characterise the changes in heart rate obtained by pulse oximetry in patients with a clinical suspicion of sleep apnoea/hypoapnoea syndrome (SAHS) using the MCT and to evaluate its diagnostic use. PATIENTS AND METHODS: A total of 187 patients were included in the study, on whom a nocturnal polysomnographic and pulse oximetry study was performed. To evaluate the variability of the heart rate the MCT applied to graphs of second order differences obtained from the heart rate record. RESULT: Patients with SAHS had a higher heart rate variability than patients without SAHS (0.449 vs. 0.666, P<0.001. In the multivariate analysis, the heart rate, the minimum saturation and the desaturation index of 4% were independently associated with the heart rate variability. As a diagnostic method, the MCT of the heart rate gives a sensitivity of 69.3%, a specificity of 77.6% and a diagnostic precision of 72.7% CONCLUSIONS: Patients with SAHS have a greater variability in heart rate during the night, evaluated by applying the MCT of the heart rate to diagrams of second order differences. As a screening method, the MCT applied to the heart rate has a moderate sensitivity and specificity.