PubMed Health⌕ Search

Biomedical subjects

W Fehske

Publications and source records attributed to W Fehske.

47 records · Page 3Linked to original sources
PubMed1990

[Computer-assisted contour detection in a complete heart cycle by levocardiography with adaptive raster tracking--validation of the method].

A method for computer-assisted edge detection in a full heart cycle of the left ventricular cineangiogram is presented. Left ventricular cineangiograms were acquired in the 30 degrees RAO position on cinefilms with 50 frames/s. A selected heart cycle was digitized with a spatial resolution of 512 x 512 pixels and a grey-value range from 0 to 255. In the first frame of the heart cycle a raster was calculated from contour points marked by an operator. The raster was automatically adapted to the left ventricular contour in the following frames. The contour points were determined on the adaptive raster by a gradient method. The automatic calculation of all contours of the systolic contraction was possible in 28 of 30 cineangiograms, operator interaction was necessary in two cineangiograms. The calculation of the diastolic contours requested operator interaction in 4 of 30 cineangiograms. The mean deviation of the calculated from the true contours ranged from -1.2 +/- 1.9 mm to 0.9 +/- 2.9 mm. The correlation coefficients between volumes calculated from the computer-determined and manually drawn contours ranged from r = 0.98 to r = 1.0 at beginning of systole, midsystole, endsystole, middiastole, and enddiastole with a standard error of the estimate between 2.8 ml and 5.2 ml. A repeated automatic determination of the contours after an independent remarking of the starting points resulted in a linear correlation of the calculated volumes with a correlation coefficient of r = 1.0 and a standard error of the estimate between 1.3 ml and 4.7 ml. The correlation coefficient for the ejection fraction was r = 0.99 with a standard error of the estimate of 1.9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Acute effects of enoximone in chronic heart failure.

In 19 patients with chronic heart failure in NYHA stages III and IV, hemodynamic measurements were made using a Swan-Ganz catheter before and 15 and 30 min after intravenous administration of enoximone. Group A (n = 10) received 1.0 mg of enoximone/kg of body weight and group B (n = 9) received 1.5 mg of enoximone/kg of body weight. In group A, there was a rise in the pulse rate of 13% and in the cardiac index of 13% with unchanged stroke volume index. At constant mean arterial pressure, the mean right atrial pressure fell by 28%, the mean pulmonary arterial pressure by 11%, the total peripheral resistance by 13%, and the total pulmonary resistance by 21% after 30 min. In group B, the pulse rate rose by 9.8%, the mean blood pressure by 2.7%, the cardiac index by 31.4%, and the stroke volume index by 18.4% 30 min after administration of enoximone, whereas a fall in the mean right atrial pressure by 57.4%, the mean pulmonary arterial pressure by 28.6%, the total peripheral resistance by 26.0%, and the total pulmonary resistance by 45.3% could be shown. At a low dosage of enoximone, the vasodilatory effects of this substance are most prominent, whereas an increase in the pumping performance of the heart could be clearly demonstrated in higher dose ranges.

Aged↗
PubMed1980

[Diagnosis and treatment of pericardial effusions with the aid of 2-dimensional Doppler echo cardiography (author's transl)].

In a case of a large acute pericardial effusion the diagnosis and the following pericardiocentesis under visible control by means of 2-dimensional echocardiography (2 D-E) are described. The effusion coat around the heart can clearly be localised. Furthermore, a new echocardiographic system is used combining 2 D-E and range-gated pulsed Doppler technique that allows the registration of flow-velocity curves in the superior vena cava and the recognition of a beginning cardiac tamponade. If indicated, the following pericardiocentesis can be done under direct ultrasonic control avoiding any risk of heart perforation.

Adolescent↗
PubMed1980

[Cardiac effects of isoproterenol in the complex echocardiographic evaluation (author's transl)].

The cardiac response to isoproterenol was examined in 10 normal subjects by echocardiography. The complete qualitative and computer-assisted quantitative analysis of one-dimensional recordings of the left ventricle is combined with two-dimensional echograms. The results - including the well-known facts that cardiac output and the velocity of contraction are increased while the end-diastolic dimensions are partly decreased - indicate that the stroke volume is not significantly diminished in the supine position. In two cases it is even enlarged. Moreover, a "pseudo-Sam" and the changes of the systolic time intervals demonstrate the strong positive inotropic effect of the drug. The amplitude of the descent of the base movement is also enlarged. The velocity of relaxation is not as increased as the velocity of contraction in that part of the posterior wall which is hit by the echobeam. There is a remarkable dissociation between the Ecg and the actual cardiac movements. E.g., with isoproterenol the mitral valve opens during the ascending T-wave, while normally relaxation only starts after complete electrical repolarisation. The shortening fractions of the phases of the cardiac cycle induced by the drug as compared to the control state are determined. It is shown that shortening of the whole cardiac cycle causes the systolic phase to shorten to a nearly adequate ratio. The slow filling phase mostly shortens to the smallest while the rapid filling phase always shortens to the greatest ratio. We discuss all echocardiographic parameters that are used for this study and we demonstrate some limitations to the interpretation of time-dimension curves derived from M-mode echocardiograms. These are especially evident after a strong beta-sympathomimetic stimulation, because after the injection of isoproterenol the appearance of the septal echo-lines changes from one subjects to the other in a striking way.

Adult↗
PubMed1978

[Determination of the severity of mitral stenosis by hemodynamic and echocardiographic parameters].

M-Mode and two-dimensional echocardiographic examinations were performed in 70 patients with pure or prevailing mitral stenosis. Mitral valve excursion, mitral valve opening area (MVOAe) and diastolic E-F slope were determined and compared with the gradient across the valve and the opening area obtained during cardiac catheterization. Mitral valve excursion and E-F slope showed mean values of 1.71 cm and 1.98 cm/sec. respectively and were indicative of a stenosed mitral valve. Correlation between E-F slope and gradient with MVOAe was poor. The correlation coefficient was r = +0.56 and r = 0.34 resp. MVOAe compared favorably to the mitral valve area determined at cardiac catheterization (r = + 0.96) and the gradient across the mitral valve (r = 0.90)9 We conclude: 1. Determination of the mitral valve opening area by means of two-dimensional echocardiography represents a valuable addition in the assessment of the severity of mitral stenosis. 2. M Mode echocardiography indicates the presence, but not the severity of mitral stenosis. 3. Computerized planimetry is superior to the manually planimetered opening area and represents a reproducible, exact and time-saving procedure.

Adult↗
PubMedDate not supplied

Multiplane transesophageal echocardiographic evaluation of transvenous defibrillation leads.

Permanent transvenous cardioverter-defibrillator leads were investigated by multiplane transesophageal echocardiography (TEE) (1) to determine whether intracardiac lead segments can be visualized, (2) to verify the position of the coils, and (3) to detect possible thrombus formation. The diagnostic information obtained in 62 patients by TEE was compared to that of transthoracic echocardiography (TTE). Abnormal findings were only visualized by multiplane TEE. However, further controlled studies are needed to determine the clinical relevance of displaced caval (one patient) and ventricular coils (15 patients), ventricular (1 patient) or atrial (6 patients) loops, and of clinically uneventful thrombi (13 patients).

Adult↗
PubMedDate not supplied

Diagnosis and follow-up of congenital heart disease in children with the use of two-dimensional Doppler echocardiography.

Two-dimensional echocardiography (2D) represents a major advance in non-invasive diagnosis of congenital heart disease (CHD) in children. Nevertheless it has diagnostic limitations in nearly all kinds of heart lesions. These can be overcome for the most part by integration of a pulsed Doppler system. This may be called two-dimensional Doppler echocardiography (2DD). Hereby blood flow information is added to the 2D image. Some common types of CHD including ventricular and atrial septal defects, persistent ductus arteriosus, pulmonic stenosis and coarctation are described with their typical 2DD findings. Non-invasive follow up of children with CHD and early recognition of typical complications can be achieved reliably using 2DD. Future prospects consist in a more quantitative diagnostic application of 2DD.

Adolescent↗
PubMedDate not supplied

Morphology of the mitral valve as displayed by multiplane transesophageal echocardiography.

This study was performed to (1) describe how multiplane transesophageal echocardiography (TEE) facilitates imaging of the entire mitral valve apparatus, and (2) prospectively compare the morphology of the different segments of the mitral apparatus as determined by multiplane TEE and direct surgical inspection. The study consisted of 30 consecutive patients examined by multiplane TEE less than 24 hours before mitral valve surgery. The mitral valve was displayed in transgastric and transesophageal views with the imaging planes specifically aligned to demonstrate continuity between the papillary muscles, chordae tendineae, and leaflet edges. The character and location of morphologic abnormalities identified by findings of preoperative TEE were highly concordant with surgical inspection of the valve (p < 0.0001). Thus multiplane TEE offers the ability to visualize the entire mitral apparatus as a functional unit and to identify morphologic abnormalities of the valve correctly.

Adult↗