Pancycle Aortic Incompetence and Double Alternans in Pediatric Heart Failure

A 12?year?old boy presented with bicuspid aortic valve, severe aortic regurgitation, and dilated dysfunctional left ventricle in heart failure. He underwent aortic valve replacement with a 23 mm TTK Chitra heart valve prosthesis (tilting disk). He was gradually weaned off milrinone and noradrenaline in the intensive care. Echocardiography showed severe left ventricular dysfunction with an ejection fraction of 24%. The radial pulse was regular and of normal volume but exactly half that of the heart rate. Evaluation of the rhythm and echocardiography revealed an interesting hemodynamic phenomenon with double alternans.

Plethysmographic variability index as a tool to assess fluid responsiveness in critically ill patients: a correlation study with inferior vena cava distensibility index

Background: In critically ill patients in the intensive care unit (ICU), early aggressive fluid replacement is the cornerstone of resuscitation. Traditionally employed static measures of fluid responsiveness have a poor predictive value. It is therefore imperative to employ dynamic measures of fluid responsiveness that take into account the heart lung interactions in the mechanically ventilated patients. The main objective of this study was to evaluate the reliability of one such non-invasive dynamic index: Plethysmographic variability index (PVI) compared to the widely employed Inferior vena cava distensibility index (dIVC).Methods: Seventy-six adult patients admitted at a tertiary care mixed ICU, who developed hypotension (MAP<65mmHg), were included in the study. PVI was recorded using the MASIMO-7 monitor and dIVC measurements done using Terason ultrasound. Based on the dIVC measurement threshold of 18%, the patients were classified into volume responders and non-responders. The hemodynamic, PVI and dIVC measurements were recorded at pre specified time points following a fluid challenge of 20 ml/kg crystalloid infusion.Results: Baseline PVI values were significantly higher in the responders (22.3±8.2) compared to non-responders (10.1±2.9) (p<0.001) and showed a declining trend at all time points in the responders. Similar declining trend was observed in the dIVC measurements. Overall, the Pearson correlation graph showed strong correlation between dIVC and PVI values at all time points (r=0.678, p=0.001). The ROC curve between the dIVC and PVI values revealed that Baseline PVI (Pre PVI) >15.5% discriminated between responders and non-responders with a 90.2% sensitivity and 75% specificity with an AUC of 0.84 (0.72-0.96) (p<0.001).Conclusions: There is good correlation between PVI values and measured dIVC values at baseline and following a fluid challenge. Thus, PVI may be an acceptable, real time, continuous, surrogate measure of fluid responsiveness in critically ill patients.

Algoritmo para la detección de puntos clínicos de interés de la onda de pulso arterial / Algorithm for the detection of clinical points of interest of the arterial pulse wave

Introducción: La aplicación de métodos para la detección de puntos clínicos de interés de la onda de pulso permite la obtención de parámetros como el índice de rigidez vascular y el de reflexión que facilitan la evaluación de los efectos vasculares del envejecimiento, la hipertensión y la aterosclerosis. Por esto es necesaria la adecuada localización del inicio, pico sistólico, incisura dicrota y el pico diastólico de la onda de pulso arterial. Objetivo: Desarrollar un algoritmo para la localización del inicio, pico sistólico, incisura dicrota y el pico diastólico de la onda de pulso arterial. Método: El algoritmo presentado utiliza la primera derivada unido a condicionales móviles para eliminar puntos no deseados, al igual que intervalos no confiables. El algoritmo fue evaluado utilizando la anotación de un experto, con 5 registros de onda de pulso arterial de 5 minutos (5236 anotaciones) y contaminadas a diferente relaciones señal ruido (15, 12 and 9 dB). Resultados: Cuando se comparó con las anotaciones de un experto el algoritmo detecto estos puntos fiduciales con una sensibilidad promedio, predictividad positiva y exactitud del 100 por ciento y mostró errores menores de 10ms. En señales de onda de pulso arterial contaminadas con ruido en ambos casos el error relativo fue menor que 2 por ciento respecto a un periodo de muestreo de 800ms. Conclusiones: el algoritmo provee una simple pero precisa detección de los puntos clínicos de interés de la onda de pulso arterial, robusto a ruido y artefactos de movimiento que pudiera ser utilizado en la evaluación del índice de rigidez y de reflexión vascular(AU)

Introduction: The application of methods for the detection of clinical points of interest of the pulse wave allows obtaining parameters such as the index of vascular rigidity and reflection that facilitate the evaluation of the vascular effects of aging, hypertension and atherosclerosis. For this reason, the appropriate localization of the onset, systolic peak, dicrotic notchs and the diastolic peak of the arterial pulse wave is necessary. Objective: To develop an algorithm for the localization of the onset, systolic peak, dicrotic notchs and the diastolic peak of the arterial pulse wave. Method: The presented algorithm uses the first derivative linked to mobile conditionals to eliminate unwanted points, as well as unreliable intervals. The algorithm was evaluated using the annotation of an expert, with 5 records of arterial pulse wave of 5 minutes (5236 annotations) and contaminated at different signal-to-noise ratios (15, 12 and 9 dB). Results: When compared with the annotations of an expert, the algorithm detected these fiducial points with an average sensitivity, positive predictivity and 100 percent accuracy and showed errors of less than 10ms. In arterial pulse wave signals contaminated with noise in both cases the relative error was less than 2 percent with respect to a sampling period of 800ms. Conclusions: the algorithm provides a simple but accurate detection of the clinical points of interest of the arterial pulse wave, robust to noise and movement artifacts that could be used in the evaluation of the stiffness index and vascular reflection(AU)

Nuevos modelos conceptual y matemático para el contorno de la onda de volumen de pulso arterial / New conceptual and mathematical forms for the contour of volume wave of arterial pulse

Introducción: El análisis del contorno de la onda de volumen de pulso arterial ha sido útil para el diagnóstico no invasivo de enfermedades cardiovasculares, pero los orígenes patofisiológicos que contribuyen a este contorno no están totalmente explicados. El objetivo de este trabajo fue hallar el nivel de coincidencia de un nuevo modelo conceptual simple, basado en las fuerzas hemodinámicas, con respecto a un nuevo modelo matemático aplicado a las diferentes clases de ondas de volumen de pulso arterial en dedos de miembros inferiores. Métodos: la propuesta del modelo conceptual se basó en que este contorno es la suma de pares de gradientes de fuerzas hemodinámicas de acción, provenientes del corazón, la aorta y el distrito arterial periférico, y las de reacción, provenientes de la pared arterial músculo-elástica bajo estudio. El modelo matemático fue diseñado como un problema de programación no lineal, para hallar las 6 incógnitas numéricas de cada par de gradientes, bajo restricciones no lineales basadas en sus relaciones temporales. Se registraron los contornos desde los dedos de miembros inferiores, en pacientes en los que se pudieran observar las 4 clases de contornos de onda de volumen de pulso arterial conocidos. Se analizó la calidad de ajuste de 4 403 contornos de onda de volumen de pulso arterial experimentales, contra su onda de volumen de pulso arterial resultante del modelo matemático, desde 123 registros de 14 pacientes (7 mujeres). Resultados: La clase III fue la predominante, las clases I y II fueron frecuentes en pacientes con menos riesgo cardiovascular y la clase IV, en los de mayor riesgo...

Introduction: The analysis of volume wave contour of arterial pulse has been useful for non-invasive diagnosis of cardiovascular diseases, but the pathophysiological origins contributing to this contour are not totally explained. The objective of present paper was to find the coincidence level of a new simple conceptual form, based on the hemodynamic strengths regarding a new mathematical form applied to different classes of volume waves of arterial pulse in toe fingers. Methods: The proposal of conceptual form was based on that this contour is the addition of pairs of action hemodynamic strengths gradients from the heart, aorta and the peripheral arterial zone and of the reactions coming from study musculoelastic arterial wall. The mathematical form was designed as a non-lineal programming problem to find the six numeral unknown quantities of each pair of gradients, under non-lineal restriction based on its temporary relations. The contours from toe fingers were registered in patients with four potential classes of volume wave known contours of arterial pulse. The fitting quality of 4 403 experimental above mentioned contours was analyzed versus the arterial pulse volume resulting from mathematical form of 123 registries of 14 patients (7 women). Results: There was predominance of III class, the I and II ones were frequent in patients with less cardiovascular risk and the IV class in those of great risk. The 64 percent of the wave volume of arterial pulse had a quality fitting > 95 percent and the 36 percent had the presence of oscillating waves from skeletal muscle. Conclusions: The coincidence of both forms is accepted to characterize in a morphologic way the contour of any class of wave volume of arterial pulse

Relación del síndrome metabólico y sus componentes con la presión del pulso en personas sin enfermedad aparente / Correlation between Metabolic Syndrome and Its Components with Pulse Pressure in Persons without Apparent Disease

Introducción La presión del pulso depende en gran medida de la rigidez arterial. Varios estudios se han centrado en el hecho de que diversos factores, entre ellos el síndrome metabólico o sus componentes, intermedian cambios que afectan en forma adversa las propiedades elásticas de las grandes arterias, acentuando su rigidez. Objetivo El propósito de este trabajo de investigación fue evaluar la influencia del síndrome metabólico y sus componentes sobre la presión del pulso en personas sin enfermedad aparente. Material y métodos Se seleccionaron al azar 1.155 individuos sin enfermedad demostrable. Se registraron las variables que definen el síndrome metabólico (ATP III): en mg/dl y en ayunas, colesterol HDL ≤ 40/50 (hombres/mujeres), triglicéridos ≥ 150, glucemia ≥ 100, perímetro de la cintura (cm) ≥ 102/88 (hombres/mujeres) y presión arterial sistólica/diastólica ≥ 130/85 mm Hg. Se compararon los valores de la presión del pulso obtenidos al agrupar a los participantes por sexo y edad. Se estableció la frecuencia de los factores que definen el síndrome metabólico y mediante regresión lineal se ajustó la presión del pulso por sexo, edad y por el conjunto de ellos. A continuación se determinó el valor ajustado de la presión del pulso correspondiente a cada factor del síndrome metabólico y se comparó con el de sujetos normales. Finalmente, se calculó la presión del pulso ajustada de acuerdo con las posibles combinaciones de tres o más factores (criterio diagnóstico de síndrome metabólico) y se comparó con la de individuos en los que no se hallaba presente ningún componente del síndrome. Resultados Características generales de los 1.155 individuos: hombres 62%, edad 38 ± 9 años (rango 20-66), perímetro de la cintura 89 ± 13 cm, triglicéridos 107 ± 74 mg/dl, glucemia 82 ± 16 mg/dl, colesterol HDL 48 ± 13 mg/dl, presión arterial sistólica 124 ± 14 mm Hg, diastólica 78 ± 9 mm Hg, presión del pulso 46 ± 9 mm Hg. Edad: 38 ± 9 años los hombres (n = 712) y 37 ± 9 años las mujeres (n = 443); p = ns. La presión del pulso fue de 48 ± 8 mm Hg en los hombres versus 43 ± 9 mm Hg en las mujeres; p < 0,001. Efecto de la edad sobre la presión del pulso: 45 ± 8 en individuos < 35 años versus 47 ± 9 en ≥ 35 años; p <0,001. Frecuencia de los distintos elementos que definen el síndrome metabólico: perímetro de la cintura ≥ 102/88 cm: 18%, glucemia ≥ 100 mg/dl: 7%, triglicéridos ≥ 150 mg/dl: 17%, colesterol HDL ≤ 40/50 mg/dl: 45%, presión arterial sistólica≥ 130 mm Hg: 40%, diastólica ≥ 85 mm Hg: 16%. Al comparar la presión del pulso ajustada delimitada por cada factor del síndrome metabólico con la de los controles se obtuvo: perímetro de la cintura ≥ 102/88 cm: 48 ± 4 versus 46 ± 3, glucemia ≥ 100 mg/dl: 52 ± 5 versus 46 ± 3, triglicéridos ≥ 150 mg/dl: 48 ± 3 versus 46 ± 4, colesterol HDL ≤ 40/50 mg/dl: 44± 3 versus 47 ± 3; presión arterial sistólica ≥ 130 mm Hg: 48 ± 4 versus 45 ± 3; diastólica ≥ 85 mm Hg: 48 ± 5 versus 46 ± 3, todas p < 0,001. Por último, se comprobó la presión del pulso ajustada de acuerdo con las posibles combinaciones de tres o más factores y se comparó con la de individuos en los que no se hallaba presente ningún componente del síndrome metabólico; el resultado fue 49 ± 5 versus 46 ± 3, p < 0,001. Conclusiones El síndrome metabólico y/o sus componentes individuales inducen una elevación de la presión del pulso, a excepción del colesterol HDL. Este efecto parece ser independiente de la edad, del sexo y de la eventual interacción entre las variables analizadas.

Background Pulse pressure depends mostly on arterial wall stiffness. Several studies have focused on the fact that many factors, including the metabolic syndrome or its components, interact to impact on great vessels elastic properties, increasing arterial wall stiffness. Objective To evaluate the influence of the metabolic syndrome and its components on pulse pressure in persons without any apparent disease. Material and Methods A total of 1.155 subjects without demonstrable disease were randomly selected. The metabolic variables defining metabolic syndrome (ATP III) were recorded: fasting HDL-cholesterol ≤40/50 mg/dl (men/women), fasting triglycerides≥150 mg/dl, fasting glycemia ≥100 mg/dl, waist circumference ≥102/88 cm (men/women) and systolic/diastolic blood pressure ≥130/85 mm Hg. Patients' pulse pressure values were compared among different groups according to gender and age. The frequency of the metabolic syndrome components was determined and pulse pressure was adjusted by gender, age and all the components using multiple linear regression analysis. The adjusted value of pulse pressure corresponding to each metabolic syndrome component was determined and compared to that of normal subjects. Finally, adjusted pulse pressure was calculated according to the possible combinations of three factors or greater (diagnostic criteria of metabolic syndrome) and was compared with that of individuals without any component of the metabolic syndrome. Results General characteristics of the 1.155 individuals: men 62%, age 38±9 years (range 20-66), waist circumference 89±13 cm, triglycerides 107±74 mg/dl, glycemia 82±16 mg/dl, HDL-cholesterol 48±13 mg/dl, systolic blood pressure 124±14 mm Hg, diastolic blood pressure 78±9 mm Hg, pulse pressure 46±9 mm Hg. Age: 38±9 years in men (n=712) and 37±9 years in women (n=443); p=ns. Pulse pressure was 48±8 mm Hg in men versus 43±9 mm Hg in women; p<0.001. Influence of age on pulse pressure: 45±8 in individuals <35 years versus 47±9 in ≥35 years; p<0.001. Frequency of metabolic syn- drome components: waist circumference ≥102/88 cm: 18%, glycemia ≥100 mg/dl: 7%, triglycerides ≥150 mg/dl: 17%, HDL-cholesterol ≤40/50 mg/dl: 45%, systolic blood pressure≥130 mm Hg: 40%, diastolic blood pressure ≥85 mm Hg: 16%. When pulse pressure adjusted by each component of the metabolic syndrome was compared to that of controls, the following values were obtained: waist circumference≥102/88 cm: 48±4 versus 46±3, glycemia ≥100 mg/dl: 52±5 versus 46±3, triglycerides ≥150 mg/dl: 48±3 versus 46±4, HDL-cholesterol ≤40/50 mg/dl: 44±3 versus 47±3; systolic blood pressure ≥130 mm Hg: 48±4 versus 45±3; diastolic blood pressure ≥85 mm Hg: 48±5 versus 46±3, all p<0.001. Finally, adjusted pulse pressure according to the possible combinations of three factors or greater was calculated and compared with that of individuals without any component of the metabolic syndrome: 49±5 versus 46±3, p<0,001. Conclusions The metabolic syndrome and/or its components induce pulse pressure elevation, except for HDL-cholesterol. This effect seems to be independent of age, gender and the eventual interaction of the variables analyzed.

Relation of Dynamic Error Analysis System and Pulse Wave Velocity Measure / 医疗卫生装备

Obiective To detect the carotid-femoral pulse wave veloeity(CF-PWV) and evaluate relation in pulse pressure (PP) and pulse wave velocity ('PWV), and prove the effect of dynamic error analysis system on pulse wave velocity measure. Methods 486 cases with essential hypertension were detected with carotid-femoral pulse wave velocity. The dynamic error was controlled in three kinds of condition: 15%>error>10%, 10%>error>5% and 5%>error, which PWV values were tested repeatedly with the effect of different errors observed. At the same time the blood pressure was measured and the pulse pressure was calculated. Results The pulse wave velocity which pulse pressure ≥60mm Hg (1mm Hg=0.133 kPa) was significantly higher than pulse pressure <60turn Hg [(14.2± 2.34)m/s and (8.5±1.81)m/s, P<0.001] . Pulse wave velocity and pulse pressure and age showed a significant positive correlation (pulse pressure r=0.529, P=0.000; age r= 0.331 P=0.003).When dynamic error is more than 10% and less than 15%, the diversity of PWV values showed the significance of statistics. Conclusion The effect of dynamic error analysis system on pulse wave velocity measure, less error test pattern is advantageous to enhance accuracy. The pulse pressure is closely related to pulse wave velocity. Arterial pulse wave velocity is a new evaluation of the indicators of arterial stiffness, and it's more scientific, accurate and eonvenient.

Índice para la evaluación de las reflexiones mediante análisis de la onda de pulso radial / Index of Pressure Wave Reflection Assessed from Radial Pulse Wave Analysis

En el presente trabajo se analiza la posibilidad de utilizar un parámetro obtenido del registro de la onda de pulso radial, el ancho de la onda sistólica, que es más sencillo de medir aún que el índice de aumentación radial y que complementaría a este último en la evaluación de la amplitud de la reflexión sistólica, directamente relacionada con el grado de disfunción endotelial y el fenómeno de aumentación aórtica. Se efectuó un estudio poblacional sobre 120 varones normotensos sanos con edades entre 17 y 65 años. Se obtuvo en ellos el registro de la onda de pulso radial en base al registro del movimiento de las paredes de la arteria mediante un sensor capacitivo aplicado sobre la zona de palpación del pulso. Cada registro se procesó y normalizó en amplitud y se calculó el índice de aumentación radial y el ancho de la onda sistólica al 50% de su altura máxima. Se halló que individuos con el mismo índice de aumentación poseían distintos valores de ancho de onda sistólica, lo cual evidencia distintos valores de amplitud de la onda reflejada. Ambos parámetros aumentaron con la edad y su correlación r resultó de 0,9. Se propone la utilización del ancho de la onda sistólica como un índice de envejecimiento alternativo, que permitiría evaluar el sistema arterial cuando la medición del índice de aumentación resultara dificultosa o la comparación entre individuos fuera ambigua.

Systolic wave width, a parameter obtained from the record of radial pulse wave, is easier to measure than the augmentation index. The aim of this study was to analyze the possibility of using systolic wave width as a complementary tool for the assessment of systolic wave reflection which is directly related to the degree of endothelial dysfunction and to aortic augmentation. We performed a population study on 120 healthy men between 17 and 65 years old with normal blood pressure. Records of the radial wave pulse were obtained, based on the movement of the arterial walls, by a capacitive sensor in contact with the surface of the wrist over the radial artery. Each record was processed and its amplitude was normalized; the augmentation index and systolic wave width at half its maximum height were calculated. We found that systolic wave width was different among subjects with the same augmentation index, showing different values of the amplitude of the reflected wave. Both parameters increased with age (r correlation value 0.9). The systolic wave width is an alternative index of ageing. It might assess the arterial system when it is difficult to measure augmentation index or when comparisons between individuals result ambiguous.

Análise espectral do pulso arterial durante a circulaçäo extracorpórea: estudo experimental em cäes / Spectral analysis of the arterial pulse during cardiopulmonary bypass: experimental study in dogs

Objetivo: Avaliar o modelo do pulso arterial através da análise espectral que melhor reproduza as condições circulatórias fisiológicas durante a circulação extracorpórea com fluxo pulsátil e laminar. Material e Métodos: Dez cães adultos submetidos à circulação extracorpórea com bomba de roletes e de fluxo pulsátil instaladas em paralelo. O fluxo da circulação extracorpórea foi ajustado ao pré-existente que foi medido com fluxômetro Statham 2200. As curvas de pressão tanto com bomba de fluxo laminar, quanto com bomba de fluxo pulsátil foram registradas em fita magnética HP Recorder e analisados pelo método Fast Fourier Transform (algoritmo CooleyTukeyl. Variou-se o período da bomba pulsátil em relação ao ciclo total de 70, 60, 50, 40 e 30%. Resultados: O traçado do pulso arterial durante o uso da bomba de roletes mostrou um onda bífida com depressão profunda seguida por outra de pico único. Foram observados, espectralmente, três componentes de mesma amplitude. O uso de bomba pulsátil proporcionou, à análise espectral, componentes harmônicos de amplitudes inversamente proporcionais à relação ejeção/ciclo...

Purpose: Spectral analysis of arterial pulse was performed during cardiopulmonary bypass with both pulsatile and continuous flow in order to evaluate the pulse model best suitable to reproduce physiological circulatory conditions. Material and Methods: Ten adult mongrel dogs were submitted to cardiopulmonary bypass with a roller pump for continuous flow and pulsatile flow pump in paralel. The physiological pressure waves, the roller pump waves and the pulsatile pump flow waves were recorded. During the pulsatil flow we varied the ejective period of the pump in relation to the total cycle by 70%, 60%, 50%, 40% and 30%. Results: The roller pump flow showed a bifid wave followed by single peak wave. During spectral analysis we observed three harmonic components of the same amplitude. The using of the pulsatile pump flow proportionated, by spectral analysis, harmonic components whose amplitudes are inversely proportional for ejection/cycle ratio...