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Biomedical subjects

P Landwehr

Publications and source records attributed to P Landwehr.

81 records · Page 5Linked to original sources
PubMed1989

[Angiography in intensive care medicine].

Angiography is rarely performed in the intensive-care ward. Indications are: pulmonary embolism, unstable angina pectoris or myocardial infarction, gastrointestinal haemorrhage, acute arterial occlusion, traumatic vascular lesions, aneurysms and if a foreign body has to be extracted. It will always be necessary to weigh the pros and cons, that is to say the risks and danger involved in transporting the patient and in performing an invasive diagnostic procedure on the one hand, and the possible therapeutic gain on the other.

Angiography↗
PubMed1989

[Aneurysma spurium of the femoral artery following heart catheterization: a prospective ultrasound study].

The incidence of femoral artery pseudoaneurysms (p.a.) complicating diagnostic catheter procedures is only reported in studies regarding clinical symptoms. Since the diagnosis of aneurysms can (provided the vessel is visible) easily be done by ultrasound we made a prospective investigation of patients following coronary angiography. The unmistakable picture of p.a. consists of a rounded sonolucent, synchronic to the heart-beat eccentric expanding structure near the femoral artery, which can be differentiated from the more echorich usually not clear confined surrounding hematoma. We found 16 p.a. (5.24%) in 305 investigated patients. The size varied from 1.5 x 1.5 to 4 x 3.5 cm. In eight cases thrombosis of the p.a. was seen in follow-up controls. Operation was performed in 8 cases. Four patients had no visible hematoma; pulsation was palpable in 10, a systolic murmur heard in 12 patients. An examination by color Doppler ultrasound was done in 11 patients. Intracavitary flow and systole-diastolic jet stream in the neck of the p.a. are typical findings. We conclude that the diagnosis of femoral artery p.a. can be done accurately by ultrasound. Its incidence in patients with diagnostic catheter procedures is higher than hitherto suspected. A mild course with spontaneous thrombosis is seen frequently. Color Doppler ultrasound is recommended as a complementary investigation. In most cases angiography seems to be unnecessary.

Aneurysm↗
PubMed1988

Conventional computerized tomography of the heart.

Ungated cardio-CT provides good morphologic information in the case of congenital heart disease, volume or pressure loading, left ventricular aneurysm, tumours, thrombi, cardiac calcifications and pericardial diseases. It allows qualitative assessments of myocardial thickness and perfusion of coronary bypass grafts. ECG-gated cardio-CT allows a quantitative assessment of systolic and diastolic myocardial thickness, volume calculation of cardiac cavities and evaluation of functional parameters. The correlation of the calculated left ventricular ejection fraction comparing laevocardiography and ECG-gated cardio-CT was poor (r = 0.7) mainly due to the comparable poor time resolution on the side of cardio-CT (approximately 0.1s). The quantitative analysis of regional wall motion based on cardio-CT showed for the diagnosis of pathologic wall motion a specificity of 80.5%, sensitivity of 73.9% and accuracy of 75.7%. Side effects must be taken into account following the injection of 200-250 ml hyperosmolar contrast medium during 5-10 minutes which causes intravascular fluid retention and cardiac volume loading. Patients prone to cardiac decompensation should be excluded from cardio-CT examinations.

Cardiomyopathy, Dilated↗
PubMed1988

[Color Doppler sonography: non-invasive potential for morphologic and functional vascular diagnosis].

A linear array colour Doppler sonographic method was used experimentally on a vessel phantom in order to determine flow velocity, and the results were compared with DSA. Both the Doppler and the DSA method showed very good agreement with true velocities (r greater than 0.97). The Doppler method underestimated flow velocity. Early clinical results indicate that colour Doppler sonography is able, at the same time, to demonstrate morphology and function (direction flow and flow velocity) of significant vascular abnormalities by a non-invasive method.

Blood Flow Velocity↗
PubMed1988

Calculation of flow velocities from the geometrical shape of contrast agent-induced time-density curves using DSA.

A method for the calculation of flow velocities in vessels is introduced. The method is validated by measurements with an artificial model. Measurements with the carrier fluids sodium chloride solution and human blood using various scattering objects, show good correlation (r greater than +0.9) of the calculated and volumetrically measured velocities. With a menu-oriented computer program, measurement of flow velocities on DSA series can be made following the routine clinical examination.

Angiography↗
PubMed1987

[Quantitative regional functional analysis of the left ventricle using ECG-directed cardiac computerized tomography].

ECG-gated cardio-CT using two different methods of subsequent calculation was performed in 152 patients to evaluate contractility of the anterior and posterior wall and apex of the left ventricle quantitatively. The results were compared with RAO laevo-cardiography. Apart from the localisation of abnormal contractility, CT diagnosis showed sensitivity, specificity and accuracy from 70% to 85%. ECG-gated CT was better at showing abnormal movements at the apex and of the anterior wall than of the posterior wall. Attempts to quantify abnormalities of the basis of laevo-cardiographic results.

Adult↗
PubMed1985

[Determination of left ventricular global ejection fraction using ECG-gated cardiac computed tomography].

The left ventricular ejection fraction was calculated in 100 patients by means of ECG-gated cardio-CT and the results compared with those obtained by laevo-cardiography. A moderately good correlation of r = 0.736 was obtained. In general, CT under-estimated the ejection fraction. The normal range of the ejection fraction obtained by CT was 62.7% +/- 12.4%. Its specificity was high at 96%, but sensitivity was low, with 48.6%.

Adult↗
PubMedDate not supplied

Failure of Wallstents in the subclavian vein due to stent damage.

Subclavian vein stenosis and thrombosis are common problems in hemodialysis patients and in the Paget--von Schrötter syndrome. Besides surgery, several less-invasive strategies as balloon angioplasty, drug-induced or mechanical thrombolysis and stenting are used in the treatment of this condition. Three cases of recurrent venous obstruction of the subclavian vein treated with placement Wallstents are described. In all three patients, rethrombosis occurred due to stent failure, two involving stent fragmentation and one, stent collapse.

Adult↗