Biomedical subjects
Publications and source records attributed to D Huerta.
The interpretation of the standard echocardiogram is difficult in patients with chest deformities or lung pathology. In these instances the sub-diaphragmatic approach yields better resolution of some structures. We discuss the techniques and the advantages of such approach.
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Comparative diagnostic capacity is analyzed between two dimensional echocardiography (E-BD), hemodynamics, surgery and the M-Mode, to accurately establish the diagnosis, variety and severity of fixed fibrous subaortic stenosis, in 29 patients, whose previous diagnosis were made by two dimensional images, using paraesternal, apical and subxiphoid long axis. Group I is made up of 17 patients who had two dimensional echocardiography, M-Mode, and catheterization; Group II is composed of 12 patients who only had two-dimensional echocardiography and M-Mode. Within Group I, hemodynamics showed subaortic gradient in 81%, transvalvular in 13% and no gradient in 6%; the ventriculography showed subaortic obstruction only in 59% of the patients and was normal in 41%. The M-Mode echocardiography registered protosystolic aortic closure (CPSAo) in 50%; the subaortic obstruction was seen as a band, in 44%, non-specific echoes in the outflow tract in 12% and this was normal in 44%. The two cases with transvalvular gradient, the M-Mode registered the subaortic band, and in the case without gradient, the ventriculography showed the subvalvular obstruction. In Group II, the diagnostic signs of M-Mode were: CPSAo in 58%, band in 17%, non specific echoes in the outflow tract in 8%, and this was normal in 75%. The results support other data in that two-dimensional Echocardiography is more sensitive and more specific than M-Mode, intraventricular pressure curves and ventriculography.(ABSTRACT TRUNCATED AT 250 WORDS)
The role of hipoxia on A-V conduction was studied in the patients with severe respiratory insufficiency. Intervals of A-V conduction were measured under basal conditions, breathing room air and with increasing atrial rates. Results are compared with those obtained after the administration of 99% oxygen. A-V conduction times were normal in all the patients while breathing room air and in response to atrial pacing. With oxygen administration most patients had a decrease in A-V conduction at the expense of a prolonged A-H time, without significant alteration of the other time intervals. A-V conduction in chronic hipoxia with a PaO2 above 28 mm Hg is not delayed. Intranodal conduction delay with oxygen administration may be due to a decrease in sympathetic nerve stimulation.
We made myocardial gammagraphies on a group of 141 patients with acute thoracic pain, using 99 mtc diphosphonates. We obtained images with three projections (LOA, LL and PA); for reading the gammagraphy we used the diagnostic criteria of Berman and Cols. Studying 106 patients with acute myocardial infarction we found affirmative diagnosis in 89 cases (83.93%). In another group, 32 patients with chest angina, the results were negative in 20 cases (62.5%). We got a total of eight false positive images in patients showing post-infarction aneurism, post-defibrillation damage, and myocardial metastatic tumors. This method showed a specificity of 62.9%. Correlation with the electrocardiogram refering to the localization of the infarction, was of 85.39%. This method proved to be of high sensibility and specificity in confirming the diagnosis of acute myocardial infarction or establishing it with certainty in some patients when the electrocardiogram fails and, in some cases, to find out about the evolution and prognostic of the acute myocardial infarction.
Echocardiographic recognition of pulmonary atresia with either ventricular septal defect or intact ventricular septum is of great value in the differential diagnosis with other forms of right ventricular outflow tract obstruction or hypoplasia of the right ventricle. We studied nine patients with pulmonary atresia seven with ventricular septal defect and two with intact ventricular septum. It was not possible in either group of these patients to register systolic opening and diastolic closure movements of the pulmonary valve. In the group with ventricular septal defect, aortic straddling was present in all cases. In one patient it was possible to register the echoes of an imperforated pulmonary valve. In the remaining patients, the differential diagnosis with persistent truncus arteriosus was not possible. M-mode and Two-dimensional echocardiographic features of pulmonary atresia with intact ventricular septum are specific of this malformation and can differentiate it from other forms of hypoplasia of the right ventricle.
It has been demonstrated that M and B mode echocardiography provides anatomical and functional information regarding the fetal heart although it's usefulness is limited. Employing a high resolution system, we studied the cardiac anatomy images as well as tomographic sections of the heart of human fetuses. Thirty fetuses, 19-41 weeks, were studied through tomographic sections of the heart in long axis, short axis, apical and subxiphoid 4 chambers view. In all fetuses a view of the majority of the cardiac structures was obtained. The sections of apical and subxiphoid four chambers, short axis and long axis were obtained in 93%, 93%, 96% and 86% respectively. This anatomical views permitted detailed identification and analysis of the four cavities, atrio- ventricular, pulmonary and aortic valves, as well as the great arteries. The aortic arch, pulmonary bifurcation, the outlet of the inferior venae cavae, the superior venae cavae and the right atrium were poorly visualized. The spinal cord and the fetal ribs in older fetuses prevented us from seeing some structures, due to a greater development in the centers of ossification. Bidimentional echocardiography was performed in 77% of the fetuses after birth, in all of them cardiac anatomy before birth is possible, making the diagnosis of major malformations in utero more feasible.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.