Search PubMed⌕ Search

Biomedical subjects

A Oppelt

Publications and source records attributed to A Oppelt.

At least 37 records · Page 2Linked to original sources
PubMed1984

Evaluation of the effect of nifedipine in men after myocardial infarction.

The acute effect of nifedipine (Adalat, Bayer) was evaluated in 54 men with a history of transmural myocardial infarction. Haemodynamic changes (in 20 patients) and/or changes in left ventricular radionuclide ejection fraction (LVREF) (41 patients) were studied. 20 to 30 min after sublingual administration of 1 Adalat capsule (10 mg nifedipine) a decrease in arterial pressure and systemic resistance, and an increase in heart rate and cardiac output were observed already at rest. During exercise (50 W) there moreover occurred a decrease in pulmonary artery pressure and in arterial oxygen tension. LVREF was pathologically reduced already at rest, and in most patients exercise led to its further decrease. LVEF increased after Adalat administration only during exercise. In men with a history of myocardial infarction without clinical manifestations of heart failure, Adalat acted predominantly as a peripheral vasodilator; a negative inotropic effect was not demonstrable. The decrease in arterial oxygen tension, observed during exercise, was not clinically important.

Adult↗
PubMed1983

Equilibrium radionuclide ventriculography in men after transmural myocardial infarction.

Using equilibrium radionuclide ventriculography, the authors investigated left ventricular ejection fraction in 10 healthy men and in 57 men who had undergone their first transmural myocardial infarction (MI) 4 to 7 months earlier, were below 65 years of age and did not present signs of heart failure at the time of examination. Resting ejection fraction in healthy men amounted to 63 +/- 5%, in patients with uncomplicated MI to 54 +/- 7%, and in patients with clinical manifestations of heart failure in the acute phase to 37 +/- 8%. Patients with anteroseptal MI showed a negative correlation between the ejection fraction, on the one hand, and the sum of Q wave voltages in the precordial ECG map and the maximum value of serum creatine kinase in the acute phase of MI, on the other hand. The ejection fraction correlated with the degree of pulmonary hypertension during exercise. At work load of 50 W the ejection fraction measured in 31 patients was not significantly different shortly before discharge from hospital and 6 months after the onset of MI.

Adult↗
PubMed1982

[Assessment of regional ventilation using the inhalation of a radioactive and an aerosol of a 113mIn-labelled colloid solution].

Two methods of assessing regional ventilation distribution-dynamic scintigraphy with 133Xe-labelled gas inhalation, and pulmonary scanning following the inhalation of 113mIn-labelled colloid aerosol-were subjected to critical review. A total of 10 normal controls, 5 cardiac patients and 12 patients with pulmonary diseases were examined using both techniques. The subjective imaged of the lungs converged only in 24% of the cases. A considerable discrepancy in the results of the two investigation procedures was noted in 76%, primarily due to the sedimentation of inhaled colloid along the air passages. It is suggested that radio-aerosol scanning cannot visualize actual distribution of ventilation throughout the lungs; however, the method can be useful in the diagnosis of minor bronchial patency disorders before dynamic investigation using 133Xe can detect any changes, or where gamma-counter and analyzer facility is not available. To provide an accurate assessment of regional ventilation, the gas inhalation method should be combined with the dynamic analysis using a gamma-counter and analyzer facility, and perhaps a computer.

Aerosols↗
PubMed1981

[Nuclear magnetic resonance tomography].

Imaging methods based on nuclear magnetic resonance allow the production of sectional images of the human body without ionizing radiation. It is possible to measure the density and relaxation times of the water protons in body fluids or tissue. This allows not only to obtain morphological information but also to get some insight into the spatial distribution of physiological data. Starting with a review of the principles of nuclear magnetic resonance it is explained how the measured signal can be associated with an image point; it is also explained what type of apparatus is necessary and what the physical limitations are. Possible risks the patient may be exposed to in an examination using nuclear magnetic resonance are discussed. The present state of the technical development enables the production of whole-body sectional images of a living person within about one minute. By means of some typical examples the nature and properties of these images are explained. Although extensive clinical studies will be necessary before a more general assessment can be made of this method, an outlook is provided on expected further developments and possible future fields of application.

Humans↗
PubMed1981

Physical principles of NMR tomography.

Using nuclear magnetic resonance tomography it is possible to produce sectional images of the density and relaxation times of the protons within the human body. After a review of the general principles of nuclear magnetic resonance it is explained how this physical effect can be used for generating tomographic images in medical diagnosis. The major components of an imaging system and the physical and technical potentials and limitations of this new method are described. The different appearance of tissue and body fluids in spin-density, T1 and T2 images, as well as resulting problems of interpretation are discussed with typical examples.

Animals↗
PubMed1979

[Lung perfusion distribution study by means of 133Xe].

A method for studying regional lung perfusion employing 133Xe is described. Simple radioisotope apparatus with two catheters was used; every isotopic diagnostic department is equipped with it. The possibility of the clinical use of this method was demonstrated in 28 patients with mitral stenosis and in 11 healthy persons. A statistically significant dependence between regional movement of the perfusion to the upper regions of the lungs and the degree of hemodynamics changes in mitral stenosis was noted. Study of the distribution of persusion may be used as a simple method for appraising the hemodynamic changes in mitral stenosis. This method is simple and not burdensome for the patient. It may be recommended first of all in repeated examinations and long-term observations over patients.

Diffusion↗
PubMed1978

Possibilities of dynamic scintigraphy in renal allografts.

Dynamic scintigraphy, a non-invasive method, is suitable due to its sparing procedure in particular in clinical conditions where more pretentious examination methods are contraindicated or risky. Very frequently it can serve as a guide for more aimed examination methods. Its diagnostic value is great in particular where pathological conditions of the efferent urinary pathways are concerned, i.e. above all fistulae. In parenchymatous lesions it provides information on focal processes of an inflammatory and non-inflammatory nature. Investigation of both functions, of perfusion and transport of hippuran is sometimes a supplement for the differentiation of ATN and rejection nephropathies. The distribution of perfusion after administration of technetate helps to detect occlusion of the afferent arteries and minor arterioles.

Adult↗
PubMed1970

Regional pulmonary function in patients with mitral stenosis in relation to haemodynamic data.

Central haemodynamics in 23 patients with mitral stenosis and 7 control subjects were compared with the results of regional lung perfusion studied by (133)Xe, pulmonary scintigraphy with (99)mTc-labelled macro-aggregates of albumin, and regional ventilation by (133)Xe.A close correlation was found between both methods assessing regional pulmonary perfusion, i.e. pulmonary scintigraphy and (133)Xe. The results show that lower lung zones, when compared with upper zones, have both worse perfusion and worse ventilation. The changed distribution of perfusion and the changed distribution of ventilation correlated significantly with central haemodynamics in these patients. The ventilation gradient can be a valuable diagnostic tool for evaluating the severity of mitral stenosis, especially in long and repeated studies, due to its simplicity for the patient.

Adult↗