La preeclampsia es precedida por alteración de la función cardiovascular / Preeclampsia is Preceded by Cardiovascular Function Abnormalities

RESUMEN Introducción: La preeclampsia (PE) se acompaña de cambios en la función cardiovascular (FCV). Sin embargo, es desconocido si los cambios preceden y persisten a la manifestación clínica de PE. Objetivos: Evaluar las diferencias en la FCV, en la semana 22 de gestación (22sg) y un año posterior al parto (1app) en las pacientes que evolucionaron a la PE vs. a la normotensión (N). También, la asociación entre la FCV en 22sg y la evolución a PE. Material y métodos: Estudio prospectivo, que incluyó 260 primíparas normotensas. Se midió en la semana 22sg y a 1app: laboratorio de rutina, proteinuria de 24horas, presión arterial (PA). Por cardiografía por impedancia: índice cardíaco (IC) y de resistencia vascular sistémica (IRVS), velocidad de onda de pulso (VOP). Se formaron 3 grupos según la evolución a: PE, G1, HTA gestacional (HG) G2, y N, G3. Los resultados se presentan como media ± DS, ANOVA y test post hoc, p < 0,05. Resultados: 12 pacientes evolucionaron a PE, 18 a HG y 220 a N. El G1 presentó en los dos tiempos de medición, valores inferiores de IC y superiores de PA, IRP y VOP comparados al G3. El G2 presentó valores intermedios entre el G1 y el G3. La VOP y el IRP en la 22sg de gestación resultaron predictores de PE. Conclusiones: Las pacientes que evolucionaron a PE presentaron en fase temprana del embarazo diferente FCV respecto a las normotensas. El diagnóstico temprano de estos cambios contribuiría a predecir la PE y prevenir sus complicaciones.

ABSTRACT Background: Preeclampsia (PE) is associated with changes in cardiovascular function (CVF), but whether these changes precede and persist in the clinical phase of the disease is still unknown. Objectives: The aim of this study was to evaluate the differences in CVF during 22 weeks of gestation and one year after delivery in patients who developed PE vs. those with normotension (N). The association between CVF on 22 weeks of gestation and the development of PE was also analyzed. Methods: We conducted a prospective study including 260 normotensive primiparous women. Routine laboratory tests, 24-hour urine protein and blood pressure (BP) were measured on 22 weeks and one year after delivery. Cardiac index (CI) systemic vascular resistance index (SVRI) and pulse wave velocity (PWV) were measured by impedance cardiography. The population was divided into three groups according to the outcome during pregnancy: PE: G1, gestational hypertension (GH): G2 and normotension: G3. The results are presented as mean ± SD, ANOVA and post hoc test, p < 0.05. Results: Twelve patients evolved to PE, 18 to GH and 220 remained with N. In G1, CI was lower and BP, SVRI and PWV were higher than in G3 on 22 weeks and one year after delivery. In G2, values were always intermediate between G1 and G3. PWV and SVRI measured on 22 weeks resulted predictors of PE. Conclusions: Patients who developed PE had different CVF in the early stage of pregnancy than those with normotension. The early diagnosis of those changes could predict PE and thus contribute to prevent its complications.

Test-Retest Reliability of Non-Invasive Cardiac Output Measurement during Exercise in Healthy Volunteers in Daily Clinical Routine / Confiabilidade Teste-Reteste de Medição Não-Invasiva de Débito Cardíaco durante Exercício em Voluntários Saudáveis sob Condições Clínicas de Rotina

Abstract Background: Thoracic bioreactance (TB), a noninvasive method for the measurement of cardiac output (CO), shows good test-retest reliability in healthy adults examined under research and resting conditions. Objective: In this study, we evaluate the test-retest reliability of CO and cardiac power (CPO) output assessment during exercise assessed by TB in healthy adults under routine clinical conditions. Methods: 25 test persons performed a symptom-limited graded cycling test in an outpatient office on two different days separated by one week. Cardiorespiratory (power output, VO2peak) and hemodynamic parameters (heart rate, stroke volume, CO, mean arterial pressure, CPO) were measured at rest and continuously under exercise using a spiroergometric system and bioreactance cardiograph (NICOM, Cheetah Medical). Results: After 8 participants were excluded due to measurement errors (outliers), there was no systematic bias in all parameters under all conditions (effect size: 0.2-0.6). We found that all noninvasively measured CO showed acceptable test-retest-reliability (intraclass correlation coefficient: 0.59-0.98; typical error: 0.3-1.8). Moreover, peak CPO showed better reliability (intraclass correlation coefficient: 0.80-0.85; effect size: 0.9-1.1) then the TB CO, thanks only to the superior reliability of MAP (intraclass correlation coefficient: 0.59-0.98; effect size: 0.3-1.8). Conclusion: Our findings preclude the clinical use of TB in healthy subject population when outliers are not identified.

Resumo Fundamento: A biorreatância torácica (BT), um método não invasivo destinado à medição do débito cardíaco (DC), mostra boa confiabilidade teste-reteste em adultos saudáveis examinados em condições de pesquisa e repouso. Objetivo: No presente estudo, avaliamos a confiabilidade teste-reteste da avaliação do DC e trabalho cardíaco (TC) durante exercício, avaliado por BT em adultos saudáveis sob condições clínicas de rotina. Métodos: 25 indivíduos realizaram teste ergométrico gradual sintoma-limitante em ambiente ambulatorial em dois dias diferentes, com intervalo de uma semana. Parâmetros cardiorrespiratórios (trabalho cardíaco, VO2máx) e hemodinâmicos (frequência cardíaca, volume sistólico, DC, pressão arterial média, TC) foram medidos em repouso e continuamente sob exercício utilizando sistema espiroergométrico e cardiógrafo de biorreatância (NICOM, Cheetah Medical). Resultados: Após 8 participantes terem sido excluídos devido a erros de medição (outliers), não houve viés sistemático em nenhum dos parâmetros em todas as condições (tamanho do efeito: 0,2-0,6). Observamos que todos os débitos cardíacos medidos de forma não invasiva apresentaram níveis aceitáveis de confiabilidade teste-reteste (coeficiente de correlação intraclasse: 0,59-0,98; erro típico: 0,3-1,8). Além disso, TC máximo apresentou melhor confiabilidade (coeficiente de correlação intraclasse: 0,80-0,85; tamanho do efeito: 0,9-1,1), seguido do DC pela BT, graças apenas à confiabilidade superior da PAM (coeficiente de correlação intraclasse: 0,59-0,98; tamanho do efeito: 0,3-1,8). Conclusão: Nossos achados impedem o uso clínico da BT em indivíduos saudáveis quando outliers não forem identificados.

Impedance cardiography in the evaluation of patients with arterial hypertension / Impedância cardiografica na avaliação de pacientes com hipertensão arterial

Arterial hypertension is responsible for high morbidity and mortality. Despite increasing awareness of the consequences of uncontrolled hypertension and the publication of several recommendations and guidelines, blood pressure control rates are suboptimal, and approximately half of the patients do not reach the targets. Defined as an increase in blood pressure, hypertension is characterized by hemodynamic abnormalities in cardiac output, systemic vascular resistance, or arterial compliance. Therefore, the approach to arterial hypertension can be improved by the knowledge of the hemodynamics underlying the blood pressure increase. Impedance Cardiography has emerged as a new strategy to customize therapy and monitor patients aiming to improve blood pressure control according to the hemodynamic profile, rather than a blind intensive care approach. This is a review of impedance cardiography evidence, its benefits, actual and future applications in the approach and management of arterial hypertension

Uso da tomografia por impedância elétrica torácica como ferramenta de auxílio às manobras de recrutamento alveolar na síndrome do desconforto respiratório agudo: relato de caso e breve revisão da literatura / Use of thoracic electrical impedance tomography as an auxiliary tool for alveolar recruitment maneuvers in acute respiratory distress syndrome: case report and brief literature review

RESUMO A tomografia por impedância elétrica torácica constitui ferramenta de monitorização não invasiva, em tempo real, da distribuição regional da ventilação pulmonar. Sua utilização à beira do leito em pacientes com síndrome do desconforto respiratório agudo tem o potencial de auxiliar na condução de manobras de recrutamento alveolar, frequentemente necessárias em casos de hipoxemia refratária. Neste relato de caso, apresentamos os resultados e a interpretação da monitorização da tomografia por impedância elétrica torácica em um paciente com síndrome do desconforto respiratório agudo, durante manobras de recrutamento alveolar, com aplicação transitória de altas pressões alveolares e titulação da pressão positiva ao final da expiração ideal. Adicionalmente, apresentamos uma breve revisão da literatura a respeito do uso de manobras de recrutamento alveolar e monitorização com tomografia por impedância elétrica torácica em pacientes com síndrome do desconforto respiratório agudo.

ABSTRACT Thoracic electrical impedance tomography is a real-time, noninvasive monitoring tool of the regional pulmonary ventilation distribution. Its bedside use in patients with acute respiratory distress syndrome has the potential to aid in alveolar recruitment maneuvers, which are often necessary in cases of refractory hypoxemia. In this case report, we describe the monitoring results and interpretation of thoracic electrical impedance tomography used during alveolar recruitment maneuvers in a patient with acute respiratory distress syndrome, with transient application of high alveolar pressures and optimal positive end-expiratory pressure titration. Furthermore, we provide a brief literature review regarding the use of alveolar recruitment maneuvers and monitoring using thoracic electrical impedance tomography in patients with acute respiratory distress syndrome.

Effect of a comprehensive ambulatory care model on outcomes of patients with acute coronary syndrome in Colombia / Efecto de un modelo integral de atención ambulatoria sobre los resultados en pacientes con síndrome coronario agudo en Colombia

OBJECTIVE: To evaluate the effect of a care program designed according to a comprehensive ambulatory care model (CACM) on the appearance of new cardiovascular/coronary events in patients with acute coronary syndrome. METHODS: Participants in this quasi-experimental intervention study included acute coronary syndrome patients 30-70 years old. The intervention group (n = 165) received care under the CACM, guided by an interdisciplinary team. The CACM included transitional care, risk stratification by severity, physiological profiling (impedance cardiography), and a treatment plan in accordance with current guidelines. The control group (n = 277) received conventional, recommended care in an ambulatory cardiac rehabilitation program. During one year of follow-up, the use of emergency and hospital services related to new cardiovascular and coronary events was evaluated. RESULTS: Differences in the numbers of cardiovascular events (P = 0.003) and coronary events (P = 0.006) experienced by patients were found between the control group and the intervention group. The instantaneous risk of a cardiovascular event (hazard ratio (HR) = 1.80; 95% confidence interval (CI): 1.17-2.75; P = 0.007) and of a coronary event (HR = 1.81; 95% CI: 1.13-2.90; P = 0.013), after adjusting for age, sex, smoking, and compromised coronary arteries, was higher in the control group than the intervention group. CONCLUSIONS: Provision of care under the CACM to patients who had experienced an acute coronary event reduced emergency room visits and rehospitalizations related to new cardiovascular and coronary events by 40%. The average "number needed to treat" (NNT) under the CACM to have an impact on one person (in this case, the prevention of one cardiovascular or coronary event), was 9 and 11 respectively, indicating it is cost-effective.

OBJETIVO:Evaluar el efecto de un programa de atención diseñado según un modelo integral de atención ambulatoria (MIAA) en la aparición de nuevos episodios cardiovasculares o coronarios en pacientes con síndrome coronario agudo. MÉTODOS: Como participantes en este estudio de intervención cuasiexperimental se incluyó a pacientes con síndrome coronario agudo de 30 a 70 años de edad. El grupo de intervención (n = 165) recibió atención mediante el MIAA, guiada por un equipo interdisciplinario. El MIAA incluyó la atención transitoria, la estratificación del riesgo según la gravedad, la realización de pruebas fisiológicas (cardiografía de impedancia) y un plan de tratamiento conforme con las directrices actuales. El grupo de referencia (n = 277) recibió la atención convencional recomendada en un programa ambulatorio de rehabilitación cardíaca. Durante el año en que se llevó a cabo el seguimiento, se evaluó el uso de los servicios de urgencia y hospitalarios relacionados con nuevos episodios cardiovasculares y coronarios. RESULTADOS: Se observaron diferencias en el número de episodios cardiovasculares (P = 0,003) y episodios coronarios (P = 0,006) experimentados por los pacientes del grupo de referencia y el grupo de intervención. El cociente de riesgo instantáneo de un episodio cardiovascular (HR = 1,80; IC de 95%: 1,17-2,75; P = 0,007) y de un episodio coronario (HR = 1,81; IC de 95%: 1,13-2,90; P = 0,013), tras ajustar para la edad, el sexo, el tabaquismo y las arterias coronarias afectadas, fue mayor en el grupo de referencia que en el grupo de intervención. CONCLUSIONES: La prestación de atención mediante el MIAA a los pacientes que habían experimentado un episodio coronario agudo redujo en 40% las visitas a servicios de urgencia y las rehospitalizaciones relacionadas con nuevos episodios cardiovasculares y coronarios. El número promedio de pacientes "que es necesario tratar" mediante el MIAA para que tenga repercusión en uno de ellos (en este caso, la prevención de un episodio cardiovascular o coronario), fue de 9 y 11 respectivamente, lo que indica que la intervención es eficaz en función de los costos.

Avaliação hemodinâmica na insuficiência cardíaca: papel do exame físico e dos métodos não invasivos / Hemodynamic assessment in heart failure: role of physical examination and noninvasive methods / Evaluación hemodinámica en la insuficiencia cardíaca: papel del examen físico y de los métodos no invasivos

Entre as doenças cardiovasculares, a insuficiência cardíaca (IC) apresenta elevada taxa de internação hospitalar, morbidade e mortalidade, consumindo grandes recursos financeiros do sistema de saúde no Brasil e em outros países. A correta determinação das pressões de enchimento do ventrículo esquerdo, por avaliação invasiva ou não invasiva, é fundamental para o adequado tratamento dos pacientes com IC crônica descompensada, considerando que a congestão é o principal fator determinante dos sintomas e da hospitalização. O exame físico tem se mostrado inadequado para prever o padrão hemodinâmico. Vários estudos sugerem que a concordância em achados de exame físico por diferentes médicos é pequena e que, por fim, as próprias alterações fisiológicas adaptativas na IC crônica mascaram importantes aspectos do exame físico. Como a avaliação clínica falha em prever a hemodinâmica e pelo fato de a utilização do cateter de Swan-Ganz de rotina não ser recomendada para esse fim em pacientes com IC, métodos de avaliação hemodinâmica não invasivos, como o BNP, o ecocardiograma e a bioimpedância cardiográfica, vêm sendo crescentemente utilizados. O presente trabalho tem por objetivo realizar, para o clínico, uma revisão da função de cada uma dessas ferramentas, na definição da condição hemodinâmica em que se encontram os pacientes com IC descompensada, visando a um tratamento mais racional e individualizado.

Among the cardiovascular diseases, heart failure (HF) has a high rate of hospitalization, morbidity and mortality, consuming vast resources of the public health system in Brazil and other countries. The correct determination of the filling pressures of the left ventricle by noninvasive or invasive assessment is critical to the proper treatment of patients with decompensated chronic HF, considering that congestion is the main determinant of symptoms and hospitalization. Physical examination has shown to be inadequate to predict the hemodynamic pattern. Several studies have suggested that agreement on physical findings by different physicians is small and that, ultimately, adaptive physiological alterations in chronic HF mask important aspects of the physical examination. As the clinical assessment fails to predict hemodynamic aspects and because the use of Swan-Ganz catheter is not routinely recommended for this purpose in patients with HF, noninvasive hemodynamic assessment methods, such as BNP, echocardiography and cardiographic bioimpedance, are being increasingly used. The present study intends to carry out, for the clinician, a review of the role of each of these tools when defining the hemodynamic status of patients with decompensated heart failure, aiming at a more rational and individualized treatment.

Entre las enfermedades cardiovasculares, la insuficiencia cardíaca (IC) presenta una elevada tasa de ingreso hospitalario, morbilidad y mortalidad, consumiendo enormes recursos financieros del sistema de sanidad en Brasil, y de otros países. La correcta determinación de las presiones en el llenado del ventrículo izquierdo, por evaluación invasiva o no invasiva, es fundamental para el adecuado tratamiento de los pacientes con IC crónica descompensada, considerando que la congestión es el principal factor determinante de los síntomas y del ingreso. El examen físico ha sido inadecuado para prever el estándar hemodinámico. Varios estudios sugieren que la concordancia en los hallazgos del examen físico por diferentes médicos es pequeña y que, las propias alteraciones fisiológicas adaptativas en la IC crónica, disimulan los importantes aspectos del examen físico. Como la evaluación clínica falla a la hora de prevenir la hemodinámica, y también por el hecho de que la utilización del catéter de Swan-Ganz de rutina no se recomiende con ese fin en los pacientes con IC, los métodos de evaluación hemodinámica no invasivos, como el PNB, el ecocardiograma y la bioimpedancia cardiográfica, están en aumento. Este trabajo pretende realizar, a favor del médico, una revisión de la función de cada una de esas herramientas, para definir la condición hemodinámica en que están los pacientes con IC descompensada, objetivando un tratamiento más racional e individualizado.

Clinical application of non-invasive hemodynamic monitoring by thoracic electrical bioimpedance in elderly non-cardiac surgery patients after general anaesthesia / 中国医师进修杂志

Objective To evaluate the application value of non-invasive hemodynamic monitoring by thoracic electrical bioimpedance (TEB) in elderly non-cardiac surgery patients after general anaesthesia.Methods Fifty-six elderly non-cardiac surgery patients after general anaesthesia were divided into control group and TEB group with 28 patients in each group by random digits table. All patients received standardized care including central venous pressure (VAP). Besides these monitoring, hemodynamic monitoring by TEB was used to evaluate the hemodynamic state of patients in TEB group. Diuretics, inotropic agents, vasoactive drugs or intravenous fluid therapy were used according to monitoring guidance. The heart rate (HR), mean arterial pressure (MAP), VAP, urine output (UO) were recorded in different time. The length of mechanical ventilation and ICU stay were also recorded. The difference in HR, MAP, VAP, UO, the length of mechanical ventilation and ICU stay between two groups were analyzed. Results The differences between two groups had no significance in HR, MAP, VAP, UO at the same time (P ＞ 0.05 ). The length of mechanical ventilation of TEB group [ (19.5±15.9)h] was shorter as compared to that of control group [ (25.5 ± 16.5) h ], but the difference was not significant (P =0.173). The ICU stay of TEB group [(2.8 ± 1.0) d ] was shorter as compared to that of control group[(3.6±1.6)d] and the difference was significant (P=0.032). Conclusion Non-invasive hemodynamic monitoring by TEB can monitor the changes of hemodynamics and direct treatment in elderly non-cardiac surgery patients after general anaesthesia.

Clinical evaluation of the accuracy of a new generation bioimpedance cardiac output monitor / 中华麻醉学杂志

Objective To evaluate the accuracy of a new generation bioimpedance cardiac output monitor as compared with thermodilution and end expiratory CO 2 techniques Methods Sixteen patients (14 males, 2 females) aged (58?12) years undergoing elective coronary artery bypass (CAB) surgery were studied Cardiac output was measured after CAB surgery in ICU using a new generation bioimpedance cardiac output monitor(Rheo Bioimpedance Hemodynamic monitor) and conventional thermodilution technique in 16 patients and end expiratory CO 2 technique in 10 patients Cardiac output was also measured with Rheo Bioimpedance Hemodynamic monitor in 200 healthy volunteers consisting of equal numbers of male and female The volunteers of each sex were further divided into 5 equal groups of 20 each: (1)20 29 years, (2)30 39 years, (3)40 49 years, (4)50 59 years and (5)60 70 years Results Cardiac outputs measured by bioimpedance and thermodilution techniques were well correlated (r=0 83) and there was also a good correlation between cardiac outputs measured by bioimpedance and end expiratory CO 2 techniques(r=0 88) Cardiac out measured with Rheo Bioimpedance Hemodynamic monitor in 200 healthy volunteers showed that there was a significant difference in cardiac output between 60 70 years age group and the other age groups in both male and female Conclusions Cardiac output and other hemodynamic parameters measured with the new generation bioimpedance hemodynamic monitor are accurate and can be used for preoperative cardiovascular function evaluation and postoperative monitoring of dynamic changes in circulatory function

The changes of pulmonary hemodynamics of pulmonary edema induced by oleic acid in rabbits / 中国病理生理杂志

It was an dideal model of respiratory distress syndyomeinduccd in 59 rabbits by Ⅳ oleic acid injection. Pulmonary hemodynamics, cardiac impedance paramcters were measured, microemboli and leukocytcs were abtained directly from the pulmonary microcirculation by use of the retrograde perfusion method. The results showed that pulmonary hemodynamics were changed significantly, but did not correlate with development of pulmonary edema. It was found that basic impedance (Zo) increased, stroke volume (SV), cardiac output (CO) and cardiac index (CI) all decreased (P