Selected Cardiovascular Studies Based on Photoplethysmography Technique

Photoplethysmography (PPG) is a simple and inexpensive optical technique that can be used to detect blood volume changes in the microvascular bed of tissues. There has been a resurgence of interest in the technique in recent years, driven by the demand for low cost, simple and portable technology for the primary care and community based clinical settings and the wide availability of low cost and small semiconductor components, and the advancement of computer-based pulse wave analysis techniques. The present research work deals with the design of a PPG sensor for recording the blood volume pulse signals and carry out selected cardiovascular studies based on these signals. The interaction of light with tissue, early and recent history of PPG, instrumentation, measurement protocol and pulse wave analysis are also discussed in this study. The effect of aging, mild cold exposure, and variation in the body posture on the PPG signal have been experimentally studied.

Prevalencia de factores de riesgo cardiovascular en niños de 3 a 17 años

Introducción: Los factores de riesgo de la enfermedad cardiovascular (FRECV) pueden estar presentes desde la infancia y predicen la enfermedad cardiovascular del adulto. Objetivo: Evaluar la prevalencia de FRECV en niños de 3 a 17 años hijos de Enfermeras de la Fundación CardioInfantil - Instituto de cardiología (FCI). Métodos: Estudio de corte transversal analítico. Resultados: 118 niños, edad promedio 7,4 años, desviación estándar 3,86, la mayoría eutróficos 72,0%. Presentaron FRECV como malos hábitos alimenticios 89,0%, sedentarismo 78,8%, exposición a tabaco 19,5%, historia familiar de riesgo cardiovascular 16,1%, sobrepeso 15,3% y obesidad 12,7%. No se encontraron diferencias entre factores de riesgo entre niños y niñas.El sedentarismo en niños con sobrepeso u obesidad fue del 90,9% y en niños eutróficos del 36,5%. Los malos hábitos alimentarios en niños con sobrepeso u obesidad fueron 84,8% y en niños eutróficos 42,4%. Los adolescentes presentaron una mayor exposición a tabaco en comparación con los preescolares y escolares, al igual que una mayor proporción de malos hábitos alimenticios en comparación con ambos grupos. De la totalidad de la población de estudio, el 97,5% presentó al menos un FRECV, y el 42,4% 3 o más FRECV. La presencia de ≥3 FRECV fue mayor en obesos al compararlos con los niños en sobrepeso y eutróficos. Conclusiones: Los resultados del estudio indican que los niños de 3 a 17 años evaluados presentan una alta carga de FRECV, en especial en aquellos con sobrepeso y obesidad.

Factores de riesgo para mediastinitis en adultos sometidos a cirugía cardiovascular Fundación Abood Shaio 2000 - 2006

La mediastinitis post cirugía cardiovascular es una complicación severa de mal pronóstico, con incidencia mundial de 0.4 al 5% y mortalidad de 8.6-42%. En Bogotá 2 trabajos de investigación reportan una incidencia de 1.7% en 1999. Se pretende establecer factores de riesgo de la enfermedad y características propias de la Fundación Abood Shaio. este estudio retrospectivo de caso y control, de Enero-2000 a Diciembre-2006, buscó identificar factores de riesgo asociados con aparición de mediastinitis postcirugía cardiovascular en la Fundación Abood Shaio. Se revisaron base de datos y registros existentes sobre 6113 cirugías cardiovasculares, encontrando 48 pacientes adultos que desarrollaron mediastinitis posquirúrgica.

Acondicionamiento físico en la disminución del riesgo cardiovascular en empresas afiliadas a seguros de vida Alfa S.A. ARP

En Estados Unidos desde el año 1900, las enfermedades cardiovasculares han sido la principal causa de muerte. Según la American Heart Association, una de cada 5 personas sufre de algún tipo de enfermedad cardiovascular.1 En Bogotá fueron la segunda causa de muerte desde el año 1998 hasta el 2002. Diseño cuasi-experimental sin grupo control equivalente, comparando antes y después de un programa de acondicionamiento físico, mets, perfiles lipídicos, glicemia e IMC en población de Seguros Alfa S.A., Seguros de Vida Alfa S.A. y Sadinsa.

Evaluación del riesgo cardiovascular relacionado con la actividad laboral: Experiencia en una empresa del estado

La incidencia y prevalencia de enfermedad y riesgo cardiovascular (RCV) se incrementan con los años, como consecuencia de la falta de control en los factores de riesgo modificables, por ejemplo el sedentarismo, principalmente observado en trabajadores de oficina. El objetivo del presente trabajo fue identificar los factores asociados con el incremento del RCV en trabajadores de una empresa del estado en Bogotá, Colombia en el año 2013, a través de un estudio descriptivo de corte transversal a partir de una base de datos suministrada por la empresa con información de 272 trabajadores. Se incluyeron variables sociodemográficas, perfil ocupacional, factores de riesgo, historia clínica y medidas metabólicas. Los datos fueron estudiados a través de análisis univariado, bivariado y multivariado de regresión logística binaria. El 100% de los empleados tiene un contrato a término indefinido, siendo el género femenino más predominante. Se identificó que el RCV presente en el 11.8% de la población se asocia principalmente con la presencia de diabetes mellitus tipo 2 (ORA 9.97; IC95% 2.14-14.96, p=0.019), la alteración en el índice de masa corporal (ORA 5.67; IC95% 4.48-9.19, p=0.026), la hipertensión arterial sistólica (ORA 3.44; IC95% 2.21-4.01, p=0.037. Además hubo una relación inversa respecto al puntaje de la escala Framingham, donde menores puntajes se asociaron a menor RCV (ORA 0.04; IC95% 0.02-0.71, p=0.029), una vez se ajustó el modelo por edad, género y antigüedad en la empresa. No se encontró relación estadísticamente significativa entre el RCV, el cargo y la antigüedad laboral. Se concluye que en esta población trabajadora, independientemente de la edad, tiempo de antigüedad en la empresa y el género, los factores de riesgo clásicos para RCV están presentes y por lo tanto se deben iniciar medidas de promoción y prevención en aras de disminuir la probabilidad que el RCV encontrado se traduzca en un evento cardiovascular y de ésta manera optimizar la productividad en esta empresa.

Capacidad predictiva del euroscore II en una cohorte de pacientes de cirugía cardiovascular en una institución de cuarto nivel de Bogotá

El EuroSCORE II es una de las escalas más empleadas como predictor de riesgo de mortalidad en los servicios de cirugía cardiovascular. Esta ha sido validada en diferentes hospitales alrededor del mundo demostrando una adecuada capacidad de discriminación. El objetivo de este estudio fue evaluar el valor predictivo de la escala de riesgo EuroSCORE II en los pacientes sometidos a Cirugía Cardiovascular en una institución de cuarto nivel de Bogotá. Metodología: Estudio de prueba diagnóstica observacional y retrospectivo de la cohorte de pacientes en una institución de cuarto nivel durante los años 2012 a 2014. Se realizó el cálculo del EuroSCORE II para cada paciente, comparando la mortalidad predicha versus la observada, de forma global y por grupo de riesgo. Resultados: Del total de la población que tuvo intervención cardiaca mayor en una institución de cuarto nivel en la cohorte estudiada se presentaron 58 casos de muerte en los treinta días posteriores a la intervención, que corresponde al 7,46%. La mortalidad esperada calculada con el EuroSCORE II fue del 9,26%, lo cual indica un buen poder de predicción para esta población. Por otro lado, la curva ROC evidencia con un valor de 0.757 del área bajo la curva, que el modelo El EuroSCORE II es un buen modelo predictivo con un adecuado valor de discriminación. Se evidenció que las variables estado crítico preoperatorio y función del ventrículo izquierdo tienen mayor peso estadístico en nuestra población objeto, con una significancia del 0,001, seguido de infarto agudo de miocardio, sexo y peso de la intervención con una significancia del 0,01. Adicionalmente, el Euroscore II tiene mejor valor predictivo cuando se realiza un solo procedimiento o revascularización, en comparación a cuando se realiza procedimientos mixtos. Se recomienda realizar un estudio multicéntrico donde se incluyan pacientes con diferentes características demográficas

​Turismo de salud cardiovascular, la otra cara del sistema colombiano

A través de casos específicos, este reportaje radial expone las diferencias existentes en el acceso al derecho fundamental de la salud por parte de ciudadanos colombianos y extranjeros que padecen alguna cardiopatía. En él se recogen voces de pacientes locales e internacionales, expertos en turismo de salud, críticos del sistema de salud en el país, personal médico, asociaciones de defensa de usuarios y representantes de hospitales y clínicas. A través de las fuentes entrevistadas se muestra por qué Colombia se ha convertido en un destino atractivo para tratamientos y procedimientos del corazón y se analiza cuáles son las principales causas de esta diferenciación entre unos pacientes y otros.

Targeting the cell cycle machinery for the treatment of cardiovascular disease

Cardiovascular disease represents a major clinical problem affecting a significant proportion of the world's population and remains the main cause of death in the UK. The majority of therapies currently available for the treatment of cardiovascular disease do not cure the problem but merely treat the symptoms. Furthermore, many cardioactive drugs have serious side effects and have narrow therapeutic windows that can limit their usefulness in the clinic. Thus, the development of more selective and highly effective therapeutic strategies that could cure specific cardiovascular diseases would be of enormous benefit both to the patient and to those countries where healthcare systems are responsible for an increasing number of patients. In this review, we discuss the evidence that suggests that targeting the cell cycle machinery in cardiovascular cells provides a novel strategy for the treatment of certain cardiovascular diseases. Those cell cycle molecules that are important for regulating terminal differentiation of cardiac myocytes and whether they can be targeted to reinitiate cell division and myocardial repair will be discussed as will the molecules that control vascular smooth muscle cell (VSMC) and endothelial cell proliferation in disorders such as atherosclerosis and restenosis. The main approaches currently used to target the cell cycle machinery in cardiovascular disease have employed gene therapy techniques. We will overview the different methods and routes of gene delivery to the cardiovascular system and describe possible future drug therapies for these disorders. Although the majority of the published data comes from animal studies, there are several instances where potential therapies have moved into the clinical setting with promising results.

Targeting stem cell niches and trafficking for cardiovascular therapy.

Regenerative cardiovascular medicine is the frontline of 21st-century health care. Cell therapy trials using bone marrow progenitor cells documented that the approach is feasible, safe and potentially beneficial in patients with ischemic disease. However, cardiovascular prevention and rehabilitation strategies should aim to conserve the pristine healing capacity of a healthy organism as well as reactivate it under disease conditions. This requires an increased understanding of stem cell microenvironment and trafficking mechanisms. Engagement and disengagement of stem cells of the osteoblastic niche is a dynamic process, finely tuned to allow low amounts of cells move out of the bone marrow and into the circulation on a regular basis. The balance is altered under stress situations, like tissue injury or ischemia, leading to remarkably increased cell egression. Individual populations of circulating progenitor cells could give rise to mature tissue cells (e.g. endothelial cells or cardiomyocytes), while the majority may differentiate to leukocytes, affecting the environment of homing sites in a paracrine way, e.g. promoting endothelial survival, proliferation and function, as well as attenuating or enhancing inflammation. This review focuses on the dynamics of the stem cell niche in healthy and disease conditions and on therapeutic means to direct stem cell/progenitor cell mobilization and recruitment into improved tissue repair.

Three dimensional analysis of cardiovascular development in mouse embryos using X-ray microcomputed tomography

Micro-computed tomography (μCT) has been successfully used to study the cardiovascular system of mouse embryos in situ. With the use of barium as a suitable contrast agent, blood vessels have been imaged and analysed quantitatively such as blood volume and vessel sizes on embryos of ages 14.5 to 16.5 days old. The advantage of using this imaging modality is that it has provided three dimensional information whilst leaving samples intact for further study.

Long-range ozone transport and its impact on respiratory and cardiovascular health in the north of Portugal

Ozone dynamics depend on meteorological characteristics such as wind, radiation, sunshine, air temperature and precipitation. The aim of this study was to determine ozone trajectories along the northern coast of Portugal during the summer months of 2005, when there was a spate of forest fires in the region, evaluating their impact on respiratory and cardiovascular health in the greater metropolitan area of Porto. We investigated the following diseases, as coded in the ninth revision of the International Classification of Diseases: hypertensive disease (codes 401-405); ischemic heart disease (codes 410-414); other cardiac diseases, including heart failure (codes 426-428); chronic obstructive pulmonary disease and allied conditions, including bronchitis and asthma (codes 490-496); and pneumoconiosis and other lung diseases due to external agents (codes 500-507). We evaluated ozone data from air quality monitoring stations in the study area, together with data collected through HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model analysis of air mass circulation and synoptic-scale zonal wind from National Centers for Environmental Prediction data. High ozone levels in rural areas were attributed to the dispersion of pollutants induced by local circulation, as well as by mesoscale and synoptic scale processes. The fires of 2005 increased the levels of pollutants resulting from the direct emission of gases and particles into the atmosphere, especially when there were incoming frontal systems. For the meteorological case studies analyzed, peaks in ozone concentration were positively associated with higher rates of hospital admissions for cardiovascular diseases, although there were no significant associations between ozone peaks and admissions for respiratory diseases.

Cardiovascular and autonomic phenotype of db/db diabetic mice

The db/db mice serve as a good model for type 2 diabetes characterized by hyperinsulinaemia and progressive hyperglycaemia. There are limited and conflicting data on the cardiovascular changes in this model. The aim of the present study was to characterize the cardiovascular and autonomic phenotype of male db/db mice and evaluate the role of angiotensin II AT(1) receptors. Radiotelemetry was used to monitor 24 h blood pressure (BP) in mice for 8 weeks. Parameters measured were mean arterial pressure (MAP), heart rate (HR) and their variabilities. In 8-week-old db/db mice, the MAP and BP circadian rhythms were not different from age-matched control mice, while HR and locomotor activity were decreased. With ageing, MAP gradually increased in db/db mice, and the 12 h light values did not dip significantly from the 12 h dark periods. In 14-week-old mice, MAP was increased during light (101 +/- 1 versus 117 +/- 2 mmHg, P < 0.01; control versus db/db mice) and dark phases (110 +/- 1.7 versus 121 +/- 3.1 mmHg, P < 0.01; control versus db/db mice). This increase in MAP was associated with a significant increase in plasma angiotensin-converting enzyme activity and angiotensin II levels. Chronic treatment with losartan (10 mg kg(-1) day(-1)) blocked the increase in MAP in db/db mice, with no effect in control animals. Spectral analysis was used to monitor autonomic cardiovascular function. The circadian rhythm observed in systolic arterial pressure variance and its low-frequency component in control mice was absent in db/db mice. There were no changes in HR variability and spontaneous baroreflex sensitivity between control and db/db mice. The results document an age-related increase in MAP in db/db mice, which can be reduced by antagonism of angiotensin II AT(1) receptors, and alterations in autonomic balance and components of the renin-angiotensin system.

HISTAMINE IN THE POSTERODORSAL MEDIAL AMYGDALA MODULATES CARDIOVASCULAR REFLEX RESPONSES IN AWAKE RATS

Centrally injected histamine (HA) affects heart rate (HR), arterial blood pressure (BP), and sympathetic activity in rats. The posterodorsal medial amygdala (MePD) has high levels of histidine decarboxylase, connections with brain areas involved with the modulation of cardiovascular responses, and is relevant for the pathogenesis of hypertension. However, there is no report demonstrating the role of the MePD histaminergic activity on the cardiovascular function in awake rats. The alms of the present work were: 1) to study the effects of two doses (10-100 nM) of HA microinjected in the MePD on basal cardiovascular recordings and on baroreflex- and chemoreflex-mediated responses; 2) to reveal whether cardiovascular reflex responses could be affected by MePD microinjections of (R)-alpha-methylhistamine (AH(3)), an agonist of the inhibitory autoreceptor H(3); and, 3) to carry out a power spectral analysis to evaluate the contribution of the sympathetic and parasympathetic components in the variability of the HR and BP recordings. When compared with the control group (microinjected with saline, 0.3 mu l), HA (10 nM) promoted an increase in the MAP(50), i.e. the mean value of BP at half of the HR range evoked by the baroreflex response. Histamine (100 nM) did not affect the baroreflex activity, but significantly decreased the parasympathetic component of the HR variability, increased the sympathetic/parasympathetic balance at basal conditions (these two latter evaluated by the power spectral analysis), and promoted an impairment in the chemoreflex bradycardic response. Microinjection of AH(3) (10 mu M) led to mixed results, which resembled the effects of both doses of HA employed here. Present data suggest that cardiovascular changes induced by baroreceptors and chemoreceptors involve the histaminergic activity in the MePD. This neural regulation of reflex cardiovascular responses can have important implications for homeostatic and allostatic conditions and possibly for the behavioral displays modulated by the rat MePD. (C) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.

The kidney in different stages of the cardiovascular continuum

Patients with chronic kidney disease are at higher risk of developing cardiovascular disease. The complex, interaction between the kidney and the cardiovascular system is incompletely understood, particularly at the early stages of the cardiovascular continuum. The overall aim of this thesis was to clarify novel aspects of the interplay between the kidney and the cardiovascular system at different stages of the cardiovascular continuum; from risk factors such as insulin resistance, inflammation and oxidative stress, via sub-clinical cardiovascular damage such as endothelial dysfunction and left ventricular dysfunction, to overt cardiovascular death. This thesis is based on two community-based cohorts of elderly, Uppsala Longitudinal Study of Adult Men (ULSAM) and Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS). The first study, show that higher insulin sensitivity, measured with euglycemic-hyperinsulinemic clamp technique was associated to improve estimated glomerular filtration rate (eGFR) in participants with normal fasting plasma glucose, normal glucose tolerance and normal eGFR. In longitudinal analyses, higher insulin sensitivity at baseline was associated with lower risk of impaired renal function during follow-up. In the second study, eGFR was inversely associated with different inflammatory markers (C-reactive protein, interleukin-6, serum amyloid A) and positively associated with a marker of oxidative stress (urinary F2-isoprostanes). In line with this, the urinary albumin/creatinine ratio was positively associated with these inflammatory markers, and negatively associated with oxidative stress. In study three, higher eGFR was associated with better endothelial function as assessed by the invasive forearm model. Further, in study four, higher eGFR was significantly associated with higher left ventricular systolic function (ejection fraction). The 5th study of the thesis shows that higher urinary albumin excretion rate (UAER) and lower eGFR was independently associated with an increased risk for cardiovascular mortality. Analyses of global model fit, discrimination, calibration, and reclassification suggest that UAER and eGFR add relevant prognostic information beyond established cardiovascular risk factors in participants without prevalent cardiovascular disease. Conclusion: this thesis show that the interaction between the kidney and the cardiovascular system plays an important role in the development of cardiovascular disease and that this interplay begins at an early asymptomatic stage of the disease process.