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Biomedical subjects

C E Silva

Publications and source records attributed to C E Silva.

15 recordsLinked to original sources
PubMed1999

Double outlet right ventricle with anterior and left-sided aorta and subpulmonary ventricular septal defect.

Double outlet right ventricle (DORV) is a heterogeneous group of abnormal ventriculoarterial connections where, by definition, both great arteries (pulmonary artery and aorta) arise primarily from the morphologically right ventricle. This condition affects 1-1.5% of the patients with congenital heart diseases, with a frequency of 1 in each 10,000 live births. We report the case of an 18-day-old infant with DORV and extremely rare anatomical features, such as anterior and left-sided aorta and subpulmonary ventricular septal defect (VSD). In addition to the anatomic features, the role of the echocardiogram for guiding the diagnosis and the surgical therapy of this congenital heart disease are discussed.

Aorta↗
PubMed1995

One-year mortality prognosis in heart failure: a neural network approach based on echocardiographic data.

OBJECTIVES: This study sought to assess the usefulness and accuracy of artificial neural networks in the prognosis of 1-year mortality in patients with heart failure. BACKGROUND: Artificial neural networks is a computational technique used to represent and process information by means of networks of interconnected processing elements, similar to neurons. They have found applications in medical decision support systems, particularly in prognosis. METHODS: Clinical and Doppler-derived echocardiographic data from 95 consecutive patients with diffuse impairment of myocardial contractility were studied. After 1 year, data regarding survival or death were obtained and produced the prognostic variable. The data base was divided randomly into a training data set (47 cases, 8 deaths) and a testing data set (48 cases, 7 deaths). Results of artificial neural network classification were compared with those from linear discriminant analysis, clinical judgment and conventional heuristically based programs. RESULTS: The study group included 57 male (47 survivors) and 38 female patients (33 survivors). Linear discriminant analysis was not efficient for separating survivors from nonsurvivors because the accuracy at the ideal cutoff value was only 67.4%, with a sensitivity of 67.5%, positive predictive value of 27.8% and negative predictive value of 91.5%. In contrast, all artificial neural networks were able to predict outcome with an accuracy of 90%, specificity of 93% and sensitivity of 71.4%, for the best artificial neural network. Both clinical judgment and automatic heuristic methods were also inferior in performance. CONCLUSIONS: The artificial neural network method has proved to be reliable for implementing quantitative prognosis of mortality in patients with heart failure. Additional studies with larger numbers of patients are required to better assess the usefulness of artificial neural networks.

Adolescent↗
PubMed1995

[Postural changes during echocardiography. Is this manoeuver necessary in the differential diagnosis of fixed and free floating thrombus?].

A case of a 62 year-old woman with mitral stenosis and thrombosis of the left atrium diagnosed by two-dimensional echocardiography (2D-Echo) is reported. During the procedure, postural changes were performed and characterized the thrombus as floating one. The postural changes during 2D-echo examination allows differential diagnosis among fixed and free floating atrial thrombus. Such postural manoeuvres are also important in evaluating prognosis and therapeutic management of mitral stenosis.

Coronary Thrombosis↗
PubMed1993

[Biplane transesophageal echocardiography. Experience with 130 outpatients].

PURPOSE: To analyse the utility of transesophageal echocardiography (TEE) as a complementary technique to transthoracic echocardiographic (TTE) comparing results and additional informations. METHODS: One hundred and thirty consecutive outpatients (66 male) submitted to TEE, with age ranging from 12 to 84 years were studied. Patients were grouped according to the main indication: evaluation of prosthetic valves, 21 patients; cardiac source of emboli, 43; diseases of the aorta, 17; infective endocarditis, 14; congenital heart diseases, 14 and other abnormalities in 21 patients. RESULTS: TEE provided additional and important information in all groups. Perivalvular leakage was observed in 42.1% of patients with prosthetic valves. Vegetations were detected in 45.5% of the suspected cases of endocarditis (missed by TTE). Dissection of aorta was diagnosed in 35.2% of patients with suspected disease and atrial septal defect was successfully recognized in 80% of the cases. No complications were observed. CONCLUSION: TEE is a safe and usefull complementary non-invasive diagnostic tool in the assessment of structures such as left atrium, left atrial appendage, thoracic aorta, prosthetic valves and in the investigation of infective endocarditis.

Adolescent↗
PubMed1992

Interpretive sets, expectancy, fantasy proneness, and dissociation as predictors of hypnotic response.

College students with no prior experience of hypnosis were assessed for fantasy proneness and dissociation. In a totally separate context, they were subsequently tested for their interpretations of hypnotic suggestions, hypnotic response expectancies, and hypnotizability. Contrary to Spanos and Gorassini's (1984) hypothesis, strategic enactment of suggested responses was rarely reported, and its endorsement was not correlated with hypnotic responsiveness. Suggestibility was significantly predicted by fantasy proneness and response expectancy, but not by dissociation. A path analysis suggested that the relation between fantasy proneness and hypnotizability was partially mediated by expectancy.

Adult↗
PubMed1990

[Echocardiographic diagnosis of accessory leaflet of mitral valve].

The accessory mitral valve leaflet is a rare cardiac congenital anomaly usually associated to complex cardiac congenital malformations. It also represents a rare cause of left ventricular outflow tract obstruction. Its diagnosis has often been ignored by conventional diagnostic methods. This fact may represent a cause for relative surgical failure, when operations for cardiac complex anomalies are performed. Echodopplercardiography is the choice and more accurate method for its diagnosis. In our case, parasternal and apical long axis planes, allowed an unmistakable visualization of a parachute shape fibrous structure, with its concave surface turned up towards the aortic valve. Chordae tendinae proper to the anomalous accessory mitral valve tissue were connected to chordae or to papillary muscles of the mitral valve. A careful echodopplercardiographic study will allow us, not only to diagnose this malformation, as well as to differentiate it from other conditions like tumors, vegetations or other types of subaortic obstruction.

Child↗
PubMed1989

The surreptitious observation design: an experimental paradigm for distinguishing artifact from essence in hypnosis.

Administered a hypnotic induction and 5 standard hypnotic suggestions twice via audiotape to a group of high-hypnotizable subjects and a group of low-hypnotizable simulators. During the first administration, subjects were led to believe that they were alone. However, their behavior was surreptitiously recorded on videotape and observed on a video monitor. The second administration occurred in the presence of an experimenter who had not been informed of group assignment. When unaware that they were being observed, simulators were significantly less responsive to suggestions than they were when openly observed. In contrast, the behavior of nonsimulating subjects was not affected by the presence of an experimenter. These data indicate that the responses of highly hypnotizable subjects to standard hypnotic suggestions cannot be accounted for in terms of simple compliance with experimental demand.

Humans↗
PubMed1989

[Doppler echocardiographic evaluation of heart transplantation].

In order to evaluate major Doppler-Echocardiographic parameters for the diagnosis of acute cardiac allograft rejection episodes a serial of 54 Doppler Echocardiograms were performed simultaneously with endomyocardial biopsy in five patients (mean age = 40.2 y/o). Measurements included: right and left chambers diameters, left ventricular (LV) myocardial diastolic thickness, LV systolic function parameters, LV mass, LV volume/mass ratio, LV isovolumic relaxation time, mitral flow peak velocities and pressure half-time. Episodes with acute rejection histopathologic findings, Billingham class III or IV, were associated to increase in LV free wall thickness and LV mass (p less than 0,005) as well as decreased isovolumic relaxation time and pressure half-time (p less than 0,001). Left ventricular systolic function parameters and heart rate were no different comparing rejection and no rejection episodes. However, in each patient, progressive lower values of LV ejection fraction were associated to higher incidence of acute rejection episodes. Isovolumic relaxation time increased promptly following immunosuppressive therapy. Thus, Doppler Echocardiography is a reliable method for early detection of acute cardiac allograft rejection and monitoring of the cardiac transplant recipient.

Adult↗