Función sistólica del ventrículo izquierdo: cómo comprenderla y analizarla / Left ventricular systolic function: How to understand it and analyze it

En los estudios de resonancia magnética cardíaca, la función sistólica del ventrículo izquierdo suele calcularse automáticamente. Entender cómo se obtiene cada parámetro de la función y el por qué de las diferencias que pueden existir entre los valores obtenidos con dos técnicas, por ejemplo ecografía y resonancia magnética, es fundamental para comprenderlas e interpretarlas adecuadamente. En este artículo se detalla el análisis habitual de la función sistólica desde un punto de vista cuantitativo y cualitativo, y se explican otros métodos que no requieren un software específico. Hemos diseñado (y lo aportamos para que pueda usarse libremente) un fichero que, empleando el programa Microsoft Excel®, permite analizar la función sistólica sencilla e intuitivamente (AU)

In cardiac magnetic resonance imaging studies, left ventricular systolic function is usually calculated automatically. To understand and interpret parameters of left ventricular systolic function correctly, it is fundamental to understand how each parameter is obtained and why values obtained with different techniques, for example, ultrasonography and magnetic resonance imaging, can differ. This article provides details about the usual analysis of systolic function from the quantitative and qualitative points of view; it also explains other methods that do not require specific software. Moreover, we provide a file that we designed for use with Microsoft Excel® to enable simple, intuitive analysis of systolic function. Readers can use this file freely (AU)

[Left ventricular systolic function: how to understand it and analyze it]. / Función sistólica del ventrículo izquierdo: cómo comprenderla y analizarla.

In cardiac magnetic resonance imaging studies, left ventricular systolic function is usually calculated automatically. To understand and interpret parameters of left ventricular systolic function correctly, it is fundamental to understand how each parameter is obtained and why values obtained with different techniques, for example, ultrasonography and magnetic resonance imaging, can differ. This article provides details about the usual analysis of systolic function from the quantitative and qualitative points of view; it also explains other methods that do not require specific software. Moreover, we provide a file that we designed for use with Microsoft Excel(®) to enable simple, intuitive analysis of systolic function. Readers can use this file freely.

Actualización de las nuevas vacunas de 2ª generación frente al rotavirus autorizadas en España: perspectivas, retos y oportunidades / Up-date of the new 2nd generation vaccines against rotavirus authorized in Spain: perspectives, challenges and opportunities

Se realiza una revisión de conjunto y puesta al día sobre la importancia del rotavirus y su implicación como fuente de gastroenteritis en el niño, haciendo unas consideraciones sobre la estructura del virus, clasificación, patogenia, clínica y tratamiento. Se revisa la respuesta inmunológica del huésped y la protección de la enfermedad por el virus salvaje, señalando cómo tras la primoinfección la reinfección es cada vez menos severa al prevenir la enfermedad diarreica grave. De una forma concisa se detalla la epidemiología y carga de la enfermedad, señalando cómo el rotavirus es el causante de más de 600.000 muertes anuales en países subdesarrollados, un número elevado de hospitalizaciones, visitas ambulatorias e infecciones nosocomiales y por ello de la elevada morbilidad y mortalidad que representa para la salud pública. Se destaca como la única intervención posible es la preventiva, dado que la mejoría lograda con las condiciones higiénico sanitarias, potabilidad del agua, acceso a la rehidratación oral, etc., no han conducido a una disminución significativa de la incidencia de la enfermedad, tanto en los países industrializados como el los de en vías de desarrollo. Se describen los serotipos y genotipos más prevalentes de rotavirus conocidos en el mundo y en nuestro país, haciendo énfasis en los serotipos emergentes en la actualidad. Se hace una revisión amplia de los principales estudios aparecidos recientemente en la literatura científica sobre las nuevas vacunas de 2ª generación frente al rotavirus autorizadas por EMEA (Agencia Europea del Medicamento) y también en Estados Unidos. Aunque las dos vacunas autorizadas en España parten de principios diferentes, tienen un objetivo común, ,la prevención de la diarrea grave por rotavirus en el niño. Dados los antecendentes acontecidos con Rotashield (primera vacuna resortatne bovina-humana utilizada en Estados Unidos frente al rotavirus y actualmente retirada del mercado) y su asociación con la invaginación intestinal, han sido necesarios amplios diseños de estudios de seguridad que incluyeran a más de 70.000 niños. Con ambas vacunas Rotarix y RotaTeq TM ha quedado suficientemente probado que no existe aumento del riesgo de invaginación intestinal asociado a la vacunación. Igualmente se han revisado los ensayos sobre eficacia, inmunogenicidad, efectos adversos, etc., que han resultado ser estadísticamente significativos y suficientemente probados dentro de los rangos permisibles en relación con losa placebos. Se relacionan las recomendaciones del ACIP (Advisory Committee Inmunization Practices) para la vacuna RotaTeq TM aparecidas recientemente. Se hacen unas breves consideraciones sobre varios de los estudios de fármaco-economía encontrados en la literatura, mostrando ser coste efectivos algunos de ellos, aunque sean necesarios otros más avanzados una vez que las vacunas estén funcionando y se fijen los precios de la inmunización para la sanidad pública. Finalmente se discuten las oportunidades, retos y perspectivas de las actuales vacunas de 2ª generación y el algunas de las futuras señalando las dificultades con las que tendrán que enfrentarse. Se llega a la conclusión de la importancia en la mentalización de los pediatras en el uso de estas nuevas vacunas, sensibilización de los padres, educación sanitaria de los mismos y la de nuestras autoridades sanitarias para su inclusión en la práctica rutinaria común de las inmunizaciones precisando estudios de fármaco-economía, cargas actualizadas y reales de la enfermedad

A general review and update are done on the importance of the rotavirus and its implication as a source of gastroenteritis in the child. Comments are made on the structure of the virus, classification, pathogeny, symptoms and treatment. The immunological response of the host on protection of wild virus disease is reviewed, indicating how, after first infection, reinfection is increasingly less severe as serious diarrheic disease is prevented. Briefly, the epidemiology and disease load are explained, indicating how the rotavirus is the cause of more than 600,000 deaths yearly in underdeveloped countries elevated, number of hospitalisations, outpatients visits and nosocomial infections and, consequently, the elevated morbidity and mortality that it represents for public health. It sands out that the only possible interventions is the preventive one, since the improvement achieved with health care hygienic conditions, water potability, access to oral rehydration, etc. have not led to a significant decrease in the disease incidence in both industrialized countries and developing ones. The most prevalent rotavirus serotypes and genotypes known in the world and in our country are described. Emphasis is placed on the current emergent serotypes. An extensive review is made of the principal studies that have recently appeared in the scientific literature on the new 2nd generation vaccines against the rotavirus authorized by the European Drug Agency (EMEA) and also in the United States. Although the two vaccines authorized in Spain come from different active ingredients, they have a common objective, the prevention of serious diarrhea dur to rotavirus in the child. Wide designs of safety studies including more than 70,000 children have been necessary given the events that have occurred with rotashield (first human-bovine reassortant rotavirus vaccine used in the United States and currently withdrawn from the market) and its association with bowel intussusception. It has been sufficiently provent that there is no increased risk of bowel invagination associated with the vaccination with both vaccines, Rotarix and RotaTeq TM. Trials on efficacy, immunogenicity, adverse events, etc. have also been reviewed. They have been statistically significant and sufficiently tested within the permissible ranges in relarionship with the placebos. A list is given of the recently appeared ACID (Advisory Committee Immunization Practices) recommendations for the RotaTeq TM. Brief comments are made on several of the pharmacoeconomics studies found in the literature, some of them being cost-effective, although more advanced ones will be necessary onec the vaccines are functioning and the immunization prices established for the public health system. Finally, the opportunities, challenges and perspectives of the current 2nd generation vaccines are discussed. In some of the future ones, the difficulties that they will have to face are indicated. The conclusion is reached on the importance of convincing the pediatricians on the use of these new vaccines, making the parents aware of it, providing both the regulatory authorities and them with health care education in order to include it within the common routine practice of immunizations. This requires pharmacoeconomics studies, with up-dated and real costs of the disease

Support vector analysis of color-Doppler images: a new approach for estimating indices of left ventricular function.

Reliable noninvasive estimators of global left ventricular (LV) chamber function remain unavailable. We have previously demonstrated a potential relationship between color-Doppler M-mode (CDMM) images and two basic indices of LV function: peak-systolic elastance (Emax) and the time-constant of LV relaxation (tau). Thus, we hypothesized that these two indices could be estimated noninvasively by adequate postprocessing of CDMM recordings. A semiparametric regression (SR) version of support vector machine (SVM) is here proposed for building a blind model, capable of analyzing CDMM images automatically, as well as complementary clinical information. Simultaneous invasive and Doppler tracings were obtained in nine mini-pigs in a high-fidelity experimental setup. The model was developed using a test and validation leave-one-out design. Reasonably acceptable prediction accuracy was obtained for both Emax (intraclass correlation coefficient Ric, = 0.81) and tau (Ric, = 0.61). For the first time, a quantitative, noninvasive estimation of cardiovascular indices is addressed by processing Doppler-echocardiography recordings using a learning-from-samples method.

Cardiac motion analysis from ultrasound sequences using nonrigid registration: validation against Doppler tissue velocity.

Early detection of cardiac motion abnormalities is one of the main goals of quantitative cardiac image processing. This article presents a new method to compute the 2-D myocardial motion parameters from gray-scale 2-D echocardiographic sequences, making special emphasis on the validation of the proposed technique in comparison with Doppler tissue imaging. Myocardial motion is computed using a frame-to-frame nonrigid registration technique on the whole sequence. The key feature of our method is the use of an analytical representation of the myocardial displacement based on a semilocal parametric model of the deformation using Bsplines. Myocardial motion analysis is performed to obtain displacement, velocity and strain parameters. Robustness and speed are achieved by introducing a multiresolution optimization strategy. To validate the method, velocity measurements in three different regions-of-interest in the septum have been compared with those obtained with Doppler tissue velocity in healthy and pathologic subjects. Regression and Bland-Altman analysis show very good agreement between the two different approaches, with the great advantage that the new method overcomes the angle-dependency limitations of the Doppler techniques, providing both longitudinal and radial measurements.

Effects of angiotensin converting enzyme inhibitors in hypertensive patients with aortic valve stenosis: a drug withdrawal study.

OBJECTIVE: To determine the effects of angiotensin converting enzyme (ACE) inhibitors in hypertensive patients with aortic valve stenosis (AS). DESIGN: Observational, drug withdrawal, single blinded study, with randomisation of the order of tests. SETTING: Hypertension and asymptomatic AS. PATIENTS AND INTERVENTIONS: 20 patients (aged 73 (9) years, valve area 0.7 (0.3) cm2, left ventricular ejection fraction > or = 45%) were enrolled. Each patient underwent two sets of tests (with and without taking the drug), each of which included clinical evaluation, Doppler echocardiogram, and symptom limited exercise echocardiography. MAIN OUTCOME MEASURES: Functional and haemodynamic variables while taking and not taking ACE inhibitors. RESULTS: Drug intervention induced no change in patients' subjective functional class. While taking ACE inhibitors, patients had a lower systolic blood pressure (140 (18) mm Hg with ACE inhibitors v 159 (12) mm Hg without ACE inhibitors, p = 0.02), a higher mean pressure gradient (34 (15) mm Hg v 28 (18) mm Hg, p = 0.037), and a higher left ventricular stroke work loss (19 (6)% v 14 (10)%, p = 0.009). Other baseline functional and haemodynamic parameters were unmodified. Five patients had an abnormal blood pressure response during one of the exercise tests (two patients while taking the drug and three patients while not taking the drug). When taking ACE inhibitors, patients had a higher stroke volume at peak stress (59 (11) ml v 54 (25) ml, p = 0.046). All other stress variables remained constant. CONCLUSIONS: In AS, the afterload relief caused by ACE inhibitors is blunted by a parallel increase in the pressure gradient. However, ACE inhibitors favourably affect stress haemodynamic function in most hypertensive patients with AS and should not be discontinued.

Evaluación de un paciente con origen anómalo congénito de las arterias coronarias mediante TC multidetector / Evaluation of a patient with congenital anomalous origins of coronary arteries using a multidetector CT (MDCT)

Se presenta el caso de un recién nacido atendido en el Servicio de Pediatría del Hospital Regional Universitario «Carlos Haya» por sepsis y enfermedad respiratoria, que desarrolló coagulopatía y shock en los primeros días, por lo que se le instauró antibioticoterapia y ventilación mecánica. La bronconeumonía inicial cursó con derrame pleural e imágenes persistentemente alteradas del hemidiafragma derecho. Al final y mediante ecografía, se estableció el diagnóstico de hernia diafragmática congénita derecha. Una vez superado el problema infeccioso, fue intervenido quirúrgicamente con éxito

We present the case of a newborn, treated in our unit for sepsis and respiratory disease. In his first few days of life, he developed coagulopathy and shock, requiring antibiotics and mechanical ventilation. The initial bronchopneumonia was associated with pleural effusion, and the imaging studies repeatedly revealed a defect in right hemidiaphragm that proved to be a congenital diaphragmatic hernia on ultrasound. Once the infection resolved, surgical repair was successfully performed

Evaluación de la afectación coronaria por enfermedad de Kawasaki mediante TC multidetector / Evaluation of coronary artery lesions secondary to Kawasaki disease using multidetector computed tomography

La enfermedad de Kawasaki es la principal causa de cardiopatía adquirida en la edad pediátrica en los países desarrollados. El seguimiento evolutivo de los pacientes que han desarrollado como secuela aneurismas coronarios a pesar del tratamiento correcto es en la actualidad un problema no resuelto de indudable trascendencia clínica. Presentamos el caso clínico de una paciente de 16 años en la que el estudio con TC multidetector permitió valorar con precisión la anatomía coronaria, resolviendo las dudas diagnósticas planteadas por la evaluación convencional con ecocardiograma

Kawasaki disease is the principal cause of acquired heart disease in children in developed countries. The follow-up of patients who develop secondary coronary aneurysms despite proper treatment remains an unsolved problem of unquestionable clinical importance. We present the case of a 16-year-old patient in whom multidetector computed tomography enabled us to meticulously assess the coronary anatomy, resolving the diagnostic doubts raised by conventional ultrasound examination

Two years' activity of the Veterinary Toxicology Attention Service of Lugo, Spain.

The Veterinary Toxicology Attention Service was created at the beginning of 2001 as the first on-line toxicology service for veterinarians and animal owners in Spain. In the present study, data about the general functioning of the Service and the toxicological analysis and consultations performed are summarized. Canine-related cases constituted the main call group and veterinary practitioners represented half of the consultations. Coordination between all veterinary toxicology services in Spain and the rest of the European Union should improve this service.

Assessment of myocardial functional recovery in reperfused AMI: the clinical impact of visual and quantitative analysis in MCE.

The need far imaging methods to evaluate myocardial microcirculation in order to improve reperfusion therapy is increasingly recognized. Myocardial contrast echocardiography (MCE) is the most widely used technique far this purpose. Most of the reports published have focused on visual analysis of MCE. However, quantitative analysis may further improve the results of MCE in this setting, as has been demonstrated in experimental models and more recently in clinical studies. Several quantitative methods have been proposed, and these will be discussed in this report.

Portable spectral Doppler echocardiographic device: overcoming limitations.

BACKGROUND: There is evidence that new portable echocardiographic devices are useful in evaluating heart anatomy and function, but a lack of Doppler modes has up to now been an important limitation in obtaining haemodynamic data. OBJECTIVES: To report the Doppler capabilities of a new hand held echocardiographic device. DESIGN: Blinded comparison of two types of echocardiography machine. SETTING: Tertiary care centre. PATIENTS: 98 consecutive patients were randomly imaged with the hand held device, with a standard platform as reference. OUTCOME MEASURES: Pulsed wave transmitral Doppler inflow tract velocities, deceleration time, and continuous wave Doppler measurements of aortic ejection and tricuspid regurgitation peak velocities were recorded. RESULTS: There was excellent agreement between the hand held device and standard echocardiography for the evaluation of diastolic E and A waves, E/A ratio, and deceleration time with pulsed wave Doppler (intraclass correlation coefficients of 0.97, 0.93, 0.90, and 0.78, respectively). In addition, good agreement was found between continuous wave Doppler measurements of aortic ejection and tricuspid regurgitation velocities (intraclass correlation coefficients of 0.96 and 0.80). However, there was a significant difference between patients with tricuspid regurgitation measured with the hand held device (25.5%) and by standard echocardiography (65.3%), resulting in misdiagnosis of eight patients with pronounced pulmonary hypertension. CONCLUSIONS: New hand held devices with Doppler capabilities overcome previous limitations in evaluating haemodynamic variables. With colour Doppler they are now suitable for the complete evaluation of valvar disease and diastolic function. However, important limitations remain in the evaluation of pulmonary pressures.

Valoración ecocardiográfica de la enfermedad valvular: avances en la cuantificación de la gravedad hemodinámica y de la función ventricular / Echocardiography assessment of valvular heart disease: advances in quantification of hemodynamic severity and ventricular function

La indicación quirúrgica del enfermo con enfermedad valvular cardíaca se basa en tres pilares clínicos: su estado sintomático, el grado de gravedad de su lesión La ecocardiografía Doppler se ha convertido en la herramienta diagnóstica más importante en la valoración de las valvulopatías por su capacidad para aportar valiosa información hemodinámica de forma exacta y no invasiva. En los últimos años, mejoras tecnológicas en la calidad de la imagen bidimensional y en la resolución Doppler han permitido desarrollar nuevos métodos para cuantificar la severidad de la insuficiencia valvular, como la anchura de la vena contracta, el área de isoconvergencia proximal, y la valoración tridimensional de los jets de regurgitación. Sobre la base de un mejor entendimiento de la dinámica de fluidos de la estenosis aórtica se han desarrollado nuevos índices de severidad hemodinámica, tales como la resistencia valvular y el índice de pérdida de trabajo ventricular izquierdo. Asimismo, la utilidad de la ecocardiografía de estrés en la valoración de pacientes con enfermedades valvulares ha sido reconocida recientemente. El presente trabajo revisa estos nuevos aspectos con especial énfasis en los conceptos teóricos y sus implicaciones clínicas (AU)

Use of contrast echocardiography in the diagnosis of subacute myocardial rupture after myocardial infarction.

Myocardial rupture is an uncommon and catastrophic complication after acute myocardial infarction. It can present in an acute form or in a subacute form, with slower hemorrhage and thrombus formation at the site of rupture. These patients can survive several hours or days before the diagnosis is confirmed and the myocardial ruptured repaired. Two-dimensional Doppler echocardiography is very useful in the diagnosis of this complication, but the number of false-positive diagnoses is high, even in the presence of a large amount of pericardial effusion. In these patients, administration of a contrast agent can be useful to demonstrate active bleeding into the pericardium. We report a case of subacute myocardial rupture for which contrast echocardiography was useful in demonstrating the presence of persistent hemorrhage into the pericardium. To reduce the number of false-positive diagnoses, contrast echocardiography should be considered in patients with possible subacute myocardial rupture.

Spatio-temporal mapping of intracardiac pressure gradients. A solution to Euler's equation from digital postprocessing of color Doppler M-mode echocardiograms.

Doppler assessment of intracardiac pressure gradients using the simplified Bernoulli equation is inaccurate in the absence of a restricted orifice. The purpose of this study is to develop a new general method to map instantaneous pressure gradients inside the heart using Doppler echocardiography. Color Doppler M-mode recordings are digitally postprocessed with a software algorithm that decodes flow velocity and fits a bivariate spatio-temporal tensor-product smoothing spline. Temporal and spatial accelerations are then calculated by analytical derivation of the fitted velocity data, allowing solution of both inertial and convective terms of Euler's equation. A database of 39 transmitral inflow and transaortic outflow color Doppler M-mode recordings from 20 patients with a number of cardiac conditions was analysed, along with matched pulsed-wave spectral recordings. A close agreement was observed between the spectral and postprocessed color Doppler velocity values (error = 0.8 +/- 11.7 cm/s), validating the data decoding and fitting process. Spatio-temporal pressure-gradient maps were obtained from all studies, allowing visualisation of instantaneous pressure gradients from the atrium to the apex during left ventricular filling, and from the apex to the outflow tract during ejection. Instantaneous pressure differences between localised intracardiac sample points closely matched previously published catheterization findings, both in magnitude and waveform shape. Our method shows that intracardiac instantaneous pressure gradients can be analysed noninvasively using color Doppler M-mode echocardiography combined with image postprocessing methods.

[Utility of SPECT with 99m Tc-tetrofosmin and stimulus with dipyridamole in patients with permanent ventricular pacemakers]. / Utilidad del SPECT con 99mTc-tetrofosmin y estímulo con dipiridamol en pacientes portadores de marcapasos ventricular permanente.

BACKGROUND AND OBJECTIVE: Patients with permanent ventricular pacemakers (PP) are a difficult subgroup to assess in the study of coronary artery disease. The objective of this study was to evaluate the diagnostic value of the myocardial perfusion scintigraphy with 99mTC-Tetrofosmin (Tc-Tf) and stimulus with dipyridamole in patients with PP and suspected coronary artery disease. PATIENTS AND METHODS: Fourteen patients with suspected coronary artery disease and without structural cardiopathy, who underwent Tc-Tf and cardiac catheterization, were studied retrospectively. Sensitivity, specificity, predictive values and Kappa index were calculated for the diagnosis of coronary artery disease, multivessel disease, and for each one of the coronary arteries (left anterior descending, right coronary, and circumflex). In addition, the correlation between the number of territories with perfusion defects and the number of diseased vessels was studied. RESULTS: In regards to the diagnosis of coronary artery disease, sensitivity, specificity, positive predictive value, negative predictive value and the Kappa index were 100%, 50%, 83%, 100% and 0.55, respectively. For multi-vessel disease, these values were 83%, 64%, 64%, 83% and 0.43 respectively. The correlation coefficient between the number of territories with perfusion defects and the number of diseased vessels was 0.61 (p = 0.02). In the diagnosis of anterior descending disease, sensitivity and specificity were 83% and 88% respectively. For the right coronary artery, these values were 100% and 44% and for the circumflex artery 38% and 83%, respectively. CONCLUSION: In patients with PP and suspected coronary artery disease, myocardial perfusion scintigraphy with Tc-Tf and stimulus with dipyridamole is of great value in the diagnosis of coronary artery disease and in the assessment of its extension.