Biomedical subjects

W Nahrendorf

Publications and source records attributed to W Nahrendorf.

9 recordsLinked to original sources

PubMed1992

A comparison of carvedilol with a combination of propranolol and isosorbide dinitrate in the chronic treatment of stable angina.

The beta-blocking and vasodilating agent carvedilol was compared with a combination of propranolol and isosorbide dinitrate (ISDN) in a double-blind, parallel-group study. After two baseline sitting bicycle exercise tests on placebo, 31 patients with chronic stable angina were asymmetrically randomized to treatment with carvedilol (25 mg b.i.d.) or propranolol-ISDN (80 mg/20 mg b.i.d.) for a period of 6 months. Further exercise tests were performed 2 h after the first dose as well as after 1, 3, and 6 months of treatment. Twenty-seven patients were considered evaluable for efficacy. Differences between the two groups were observed with emphasis on total exercise time and time to 1-mm ST-segment depression. In contrast to a greater peak effect of the first propranolol/ISDN dose, the chronic antianginal and anti-ischemic effects of carvedilol at trough were found to be more marked than those of the combination.

Adrenergic beta-Antagonists↗

PubMed1992

Screening of pulmonary hypertension in chronic obstructive pulmonary disease and silicosis by discriminant functions.

The aim of our prospective multicentric study was to develop a screening method for pulmonary hypertension in patients with chronic lung diseases. We investigated 710 patients in 10 hospitals: 315 males and 109 females with chronic obstructive pulmonary disease, and 286 males with silicosis. Manifest pulmonary hypertension was defined as pulmonary artery pressure greater than 20 mmHg (2.7 kPa) at rest. The multivariate statistical method used was a stepwise discriminant analysis. In males with chronic obstructive pulmonary disease, the diameter of the right descending pulmonary artery, forced expiratory volume in one second (FEV1) arterial oxygen tension (PaO2) at rest, and age turned out to be relevant for discrimination of groups with and without manifest pulmonary hypertension. For females the FEV1/FVC (forced vital capacity) ratio replaced the absolute value of FEV1 in the calculated discriminant function. In females, sensitivity and specificity were below 80%. In males, both were distinctly above 80%. In silicosis, the diameter of the right descending pulmonary artery was much less important, since it could frequently not be measured precisely. In these cases, precision of the prediction of about 80% could only be obtained by combined evaluation of spirometry, PaO2 during exercise, and body plethysmography. The calculated discriminant functions are appropriate for screening patients with risk of pulmonary hypertension. For different chronic lung diseases, and for both sexes, different combinations of parameters are relevant. The method is recommended to select patients who should undergo an invasive examination of pulmonary haemodynamics.

Discriminant Analysis↗

PubMed1987

[Contractility parameters of the right heart in patients with chronic obstructive lung diseases without pulmonary hypertension].

By means of the radionuclide ventriculography certain contractility parameters of the right heart are presented in 15 patients with chronic obstructive bronchitis without pulmonary hypertension. The results confirm that also without increase of the pulmonary arterial blood pressure the ejection fraction of the right ventricle in rest is decreased in possible dependence upon the size hypoxaemia. The increase of the ejection fraction of the right ventricle under stress is insufficient in 7 out of 15 patients, in which case a connection with the left-ventricular ejection fraction is observed. A characteristic valuation of the right- and left-ventricular ejection fraction for pathophysiology and prognosis of the pulmonary heart disease is discussed. The necessity of further investigations is emphasized.

Adult↗

PubMed1986

[Diagnostic value of R amplitude behavior at a recording site below the conventional thoracic wall recording in the diagnosis of chronic ischemic heart disease].

Sensitivity and specificity of the behaviour of the R-amplitudes under exercise are investigated at an additional lead position on the anterior chest wall, which in previous multi-electrode-examinations showed a higher sensitivity than the conventional Wilson-leads V 4 and V 5. For the criterion "increase of R-amplitudes" could certainly be confirmed a higher sensitivity at the additional lead position, the bad specificity both at the conventional and at the additional lead position allows, however, only the inclusion of the decrease of the physiological R-amplitude into the exclusion diagnostics of the chronic ischaemic heart disease.

Adult↗

PubMed1986

[Regional differences in frequency-corrected QT duration in multi-electrode ECG in ventricular extrasystole].

Issuing from the pathophysiological significance of a prolongation of the QT-time for the diagnostics and therapy of ventricular arrhythmias examinations on 15 patients with ventricular extrasystoles by means of multi-electrode-ECG are demonstrated in comparison to 10 test persons with healthy heart. 2 regions on the thoracic surface with significant prolongation of the QT-time in the group of patients are described: Regio hypochondriaca parasternally left and left posterior axillary line at the level of the 7th and 8th thoracic vertebral body.

Arrhythmias, Cardiac↗

PubMed1986

[Studies of heart function using apex cardiography in pregnancy-induced hypertension before and following therapy with dihydralazine sulfate].

The apex cardiogram and its 1st differential quotient were simultaneously registered with the phonocardiogram, the electrocardiogram and the curve of the carotid pulse in 10 female patients with pregnancy-induced hypertension before and after the therapy with dihydralazine sulphate. 10 healthy pregnant women of the same trimenon served as comparative group. Altogether 20 parameters were investigated which are regarded as acknowledged indices of the compliance, the contractility and the ability of relaxation. The changes which we found point to an increase of the preload in H-gestosis, which seems to be regressive after the therapy with dihydralazine sulphate. The parameters of contractility and relaxation, including the systolic time intervals, remained uninfluenced.

Blood Pressure↗

PubMed1983

[ECG mapping studies for optimal electrode placement for the detection of stress-induced changes in R-amplitude in the diagnosis of chronic ischemic heart disease].

The evidence on the clinical relevance of the behaviour of the R-amplitude under load for the non-invasive diagnosis of the chronic ischaemic heart disease is contradictory in literature. One of the causes for the variable estimation is possibly to be found in the different localization of the lead electrodes. With the help of the ECG mapping using 30 electrodes at the anterior thoracic wall 15 males were examined with typical syndrome of angina pectoris and a clearly pathological reaction of the ST-distance in a preceding usual bicycle ergometry. The ECG mapping was carried out before, during and after an ergometer load in lying position with 50 Watt. The most frequent pathological reactions of the R-amplitude were found below the chest wall electrodes V4, V5 and V6 after Wilson. The estimation of the valency of this first observation must be performed in further examinations.

Aged↗

PubMed1982

[Presentation of multidimensional observed vectors in the form of trigonometric functions, explained by means of an example from internal medicine].

In the present paper a method of the graphic representation of multivariate data is described which depicts the vectors of the measuring values in form of trigonometric functions. The usefulness of this form of representation is demonstrated with the help of a material of medical data from the field of diseases of the thyroid gland. Here a comparison with the representation of multidimensional vectors of the observed values in form of graphs or in form of transformation into the plane emphasizes the good perceptibility of particularities of the data.

Data Display↗

PubMed1980

[A graphic representation of multivariate data].

In the present paper three methods of the graphic representation of multivariate data are described. One method represents the multivariate vectors of the measuring value in form of graphs, whereas the two other methods are based on transformations into the plane and produce point diagrams. The efficacy of the representation methods is demonstrated with the help of a material of medical data from the field of diseases of the thyroid gland.

Data Display↗