Dynamic three-dimensional reconstruction of the heart by transesophageal echocardiography

OBJECTIVE: To evaluate echocardiography accuracy in performing and obtaining images for dynamical three-dimensional (3D) reconstruction. METHODS: Three-dimensional (3D) image reconstruction was obtained in 20 consecutive patients who underwent transesophageal echocardiography. A multiplanar 5 MHz transducer was used for 3D reconstruction. RESULTS: Twenty patients were studied consecutively. The following cardiac diseases were present: valvar prostheses-6 (2 mitral, 2 aortic and 2 mitral and aortic); mitral valve prolapse- 3; mitral and aortic disease - 2; aortic valve disease- 5; congenital heart disease- 3 (2 atrial septal defect- ASD - and 1 transposition of the great arteries -TGA); arteriovenous fistula- 1. In 7 patients, color Doppler was also obtained and used for 3D flow reconstruction. Twenty five cardiac structures were acquired and 60 reconstructions generated (28 of mitral valves, 14 of aortic valves, 4 of mitral prostheses, 7 of aortic prostheses and 7 of the ASD). Fifty five of 60 (91.6%) reconstructions were considered of good quality by 2 independent observers. The 11 reconstructed mitral valves/prostheses and the 2 reconstructed ASDs provided more anatomical information than two dimensional echocardiography (2DE) alone. CONCLUSION: 3D echocardiography using a transesophageal transducer is a feasible technique, which improves detection of anatomical details of cardiac structures, particularly of the mitral valve and atrial septum.

Study of Coronary Flow Reserve with Intravenous Use of Microbubbles (Contrast Echocardiography) and Adenosine: Protocol for Clinical Application in Patients Suspected of Having Coronary Heart Disease

OBJECTIVE: To test the feasibility, safety and accuracy of the adenosine protocol in the study of myocardial perfusion with microbubbles contrast echocardiography. METHODS: 81 pts (64 male, 60+11 years) were submitted to contrast echocardiography with PESDA (sonicated solution of albumin 20%-1ml, dextrose 5%-12ml and deca-fluorobutane gas-8ml) to study the myocardial perfusion at rest and after bolus injection of adenosine (6 to 18mg) and to coronary angiography within 1 month each other. For each patient 3 left ventricle perfusion beds were considered (total of 243 territories). 208 territories were analyzed and 35 territories were excluded. PESDA was continuously infused (1-2ml/min), titrated for best myocardial contrast. Triggered (1:1) second harmonic imaging was used. RESULTS: Coronary angiography showed 70 flow limiting (> 75%) lesions and 138 no flow limiting lesions. At rest an obvious myocardium contrast enhancement was seen in at least 1 segment of a territory in all patients. After adenosine injection an unquestionable further increase in myocardial contrast was observed in 136 territories (99%) related to no flow limiting lesions, lasting < 10 s, and a myocardial perfusion defect was detected in 68 territories (97%) related to flow limiting lesions. It was observed only 4 false results. There were no serious complications. CONCLUSION: Myocardial perfusion study with PESDA and adenosine protocol is a practical, safe and accurate method to analyze the coronary flow reserve.

Echocardiographic Assessment of the Pulmonary Venous Flow: An Indicator of Increased Pulmonary Flow in Congenital Cardiac Malformations

OBJECTIVE: To identify the left inferior pulmonary vein as an indirect marker of increased pulmonary flow in congenital heart diseases.METHODS: We carried out a prospective consecutive study on 40 patients divided into 2 groups as follows: G1 - 20 patients diagnosed with congenital heart disease and increased pulmonary flow; G2 (control group) - 20 patients who were either healthy or had congenital heart disease with decreased or normal pulmonary flow. We obtained the velocity-time integral of the left inferior pulmonary vein flow, excluding the "reverse A" wave, with pulsed Doppler echocardiography.RESULTS: In G1, 19 out of the 20 patients had well-identified dilation of the left inferior pulmonary vein. No G2 patient had dilation of the left inferior pulmonary vein. Dilation of the left inferior pulmonary vein in conditions of increased pulmonary flow had sensitivity of 95%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 95% (1 false-negative case). The integral of time and velocity of the pulmonary venous flow obtained with pulsed Doppler echocardiography was greater in the G1 patients (G1=25.0±4.6 cm versus G2=14.8±2.1 cm, p=0.0001).CONCLUSION: The identification of dilation of the left inferior pulmonary vein suggests the presence of congenital heart disease with increased pulmonary flow. This may be used as an indirect sign of increased flow, mainly in malformations of difficult diagnosis, such as atrial septal defects of the venous sinus or coronary sinus type.

Study of Coronary Sinus Flow Reserve Through Transesophageal Doppler Echocardiography in Normal Subjects

OBJECTIVE - To evaluate the Coronary Flow Reserve in the Coronary Sinus through transesophageal Doppler echocardiography in normal subjects. METHODS - We obtained technically adequate flow samples for analysis in 10 healthy volunteers (37±8 years, 5 men) with no history of heart or systemic disease and with mean left ventricular mass index by transthoracic echocardiography of 87±18 g/m². Coronary sinus flow velocity was recorded within the coronary sinus with the patient in a resting condition and during intravenous adenosine infusion at a dose of 140 µg/kg/min for 4 minutes. Recording of coronary sinus blood flow was possible in all cases with measurement of peak systolic, diastolic, and retrograde velocities (PSV, PDV, and PRV, cm/sec), mean systolic and diastolic velocities (MSV and MDV, cm/sec), and systolic and diastolic velocity time integral (VTI S and VTI D, cm/sec). RESULTS - The coronary flow reserve was calculated as the ratio between the blood flow in the basal state and the maximum measured hyperemic blood flow with adenosine infusion. Results are shown as mean and standard deviations. (CFR = PSV + PDV -- PRV/basal PSV): 1st min = 2.2±0.21; 2nd min = 3±0.3; 3rd min = 3.4±0.37; 4th min = 3.6 ± 0.33. CONCLUSION - Although coronary sinus flow had significantly increased in the first minute, higher velocities were seen at third and fourth minutes, indicating that these should be the best times to study coronary sinus flow with intravenous adenosine in continuous infusion.

Parâmetros diretos do duplex scan no diagnóstico da estenose da artéria renal: estudo de validação e otimização dos pontos de corte

OBJETIVO: Testar o desempenho dos parâmetros diretos do duplex scan no diagnóstico da estenose da artéria renal (EAR) e verificar se os pontos de corte recomendados pela literatura são os mais adequados para se discriminar a gravidade da lesão. MÉTODOS: Estudo prospectivo, incluindo 62 pacientes portadores de EAR, submetidos ao duplex scan, seguido da arteriografia seletiva. O pico de velocidade sistólico (PVS) e a relação renal-aorta (RRA) foram mensurados. A análise estatística incluiu a curva ROC (receiver operating characteristic curve), t test student não pareado a sensibilidade, especificidade, os valores preditivos positivo e negativo, e a acurácia. RESULTADOS: A arteriografia revelou EAR 0-59% em 31 artérias (24%); EAR 60-99% em 91 artérias (72%) e 5 oclusões (4%). A análise de ROC mostrou que o PVS e a RRA apresentaram desempenho semelhante na detecção da lesão, cujas áreas sob as curvas foram 0,96 e 0,95, respectivamente. Considerando os pontos de corte recomendados pela literatura, o PVS de 180 cm/s apresentou sensibilidade de 100% e especificidade de 81%, enquanto que a RRA de 3,5 apresentou sensibilidade de somente 79%, com 93% de especificidade. Estes parâmetros foram analisados de forma conjugada (critério direto), revelando 79% de sensibilidade e 97% de especificidade. Os pontos de corte otimizados foram: PVS de 189 cm/s e RRA de 2,6, demonstrando 100%, 87%, 96% e 87% de sensibilidade e especificidade para o PVS e para a RRA, respectivamente. CONCLUSÃO: O uso isolado do PVS otimizado apresentou o melhor desempenho na detecção e na graduação da EAR.

El rol del Color en la definición del ambiente urbano de la ciudad de Córdoba. Parte II

[El proyecto consta de dos líneas de trabajo: "El rol del color en la relación edificio-entorno inmediato" y "El rol del color en el equipamiento urbano"] Objetivos generales y específicos: "Rol del color en la relación edificio-entorno inmediato". Brindar una herramienta conceptual y operativa para arquitectos, ingenieros, usuarios y todos aquellos operadores de la ciudad brindando un ámbito de reflexión y puesta en valor del fenómeno cromático a fin de consolidar una actitud respetuosa frente a la relación arquitectura-ciudad. Promover una actitud en los diseñadores que haga consciente la variable del color desde el inicio del proceso de diseño fundamentando así, los criterios de selección de tecnología, materiales y aspectos constructivos, como así también las decisiones sobre la forma, expresión y significado de los hechos arquitectónicos. Se podrá hacer extensiva una acción de servicio como asesoramiento para toda intervención cromática ya sea en la ciudad o a usuarios diversos por medio de asociaciones intermedias o gubernamentales. Es fundamental proponer un llamado de atención sobre el uso indiscriminado del color que actualmente se realiza en fachadas de edificios y medianeras urbanas, con un espíritu decorativo y mercantilista, muy lejos de mantener criterios aceptables para el reciclaje y/o puesta en valor de edificios en caso de ser considerados como patrimonio urbano. Llamado de atención que se hace extensivo al caos imperante y la polución visual de la ciudad, sin control por la carencia de normativas que orienten a una mayor y mejor legibilidad, orientación y sentido de lugar urbano. Objetivos generales y específicos: "Rol del color en la relación en el equipamiento urbano". Promover una nueva metodología de pensamiento en el proceso de ideación en el hacer de la ciudad. Concientizar a los operadores de la ciudad, sean éstos usuarios, arquitectos, ingenieros, publicistas, diseñadores industriales, del problema actual del caos visual originado por la multiplicidad de mensajes y polución visual que genera el uso indiscriminado del color. Corroborar el uso de códigos internacionales utilizados en los distintos tipos de equipamientos urbanos. Proponer una categorización y sistematización de los elementos considerados como componentes del equipamiento urbano. Promover el buen uso del color y la tecnología en el diseño del equipamiento urbano, adoptando criterios que refuercen la identidad de cada ambiente.

Genera mammalium, por Angel Cabrera. Monotremata, Marsupialia (con 19 láminas en color)

(1919)

Electrokinetic flow and transport in porous media : experimental methods, numerical analysis, and applications

Electrokinetic transport, electrochromatography, electroosmotic flow, electrophoresis, concentration polarization, fixed beds, monoliths, dynamic NMR microscopy, quantitative confocal laser scanning microscopy, mathematical modelling, numerical analysis

Anisotropy effects during unstable step flow growth

Step flow growth, meandering instability, coarsening

Chromatic responses in human visual cortex : effects of color, velocity and contrast

fMRI, color, colour, velocity, speed, contrast, cone contrast, V1, V4, hV4, MT, MT+, V3A, BOLD, Retinotopic Mapping, Contrast Response Function

Flow and transport in electrochromatography

Analyte retention, analyte transport, axial dispersion, adsorption, charge-selectivity, concentration polarization, confocal laser scanning microscopy, donnan-exclusion, electrical double layer; electrochromatography; electrohydrodynamics, electrokinetic instability, electroosmosis; electroosmotic flow; electroosmotic mobility, electroosmotic perfusion, electrophoresis, hierarchical porous media, hydrodynamic flow, induced-charge electroosmosis, ion-permselectivity, ion-permselective transport, monolith, nonequilibrium electrical double layer, nonequilibrium electrokinetic effects, nonlinear electroosmosis, plate height, plate number, porous media, pore-scale dispersion, refractive index matching, space charge effects, sphere packing, quantitative imaging, wall effect, zeta-potential