GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Analysis of the acoustic response of vascular tissue irradiated by an ultraviolet laser pulse (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 1847-1849 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Stress waves were generated in sections of human vascular tissue by transmitting laser pulses from a XeCl laser source through a glass fiber. Needle-type polyvinylidenefluoride hydrophones were used to detect the acoustic response of the tissue samples during ablation. The experimental arrangement allowed the discrimination in vitro between calcified hard tissue and normal arterial wall immersed in normal saline solution. Atheromatous vessels exhibited a shorter rise time and a higher peak stress than normal tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350356
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Interobserververgleich der quantitativen lokalen Wandfunktionsanalyse des linken Ventrikels bei der Belastungscineventrikulographie (1988)
    Springer
    Journal of molecular medicine 66 (1988), S. 482-487 
    Details
    ISSN: 1432-1440
    Keywords: Ventriculography ; Bicycle ergometry test ; Global and local left ventricular function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary During diagnostic heart catheterization biplane cineventriculograms of 46 patients at rest and directly after bicycle ergometry (72.8±27.8 W) were performed. The aim of the study was to determine the value of local wall motion analysis under physical exercise. Therefore two observers independently analyzed global and local left ventricular parameters. 38 patients had coronary artery disease, 23 with a history of myocardial infarction. Enddiastolic (EDV) and endsystolic volume (ESV) were evaluated and ejection fraction (EF) was calculated. Local wall motion was analyzed using a radial model with 60 radii in the 30° RAO- and 60° LAO-Projektion. A systolic segmental shortening was determined for the anterobasal (AB), anterolateral (AL), apical (AP), diaphragmatic (DP), posterobasal (PB) (30°-RAO), septal (SE) and posterolateral (PL) area (60°-LAO). Global functional parameters (EDV, ESV, EF) revealed good correlations between both observers with correlation coefficients (r) varying from 0.83 to 0.92. Local wall motion had sufficient correlations (r) at rest and during exercise (data in brackets) in the RAO-projektion: AB: 0.88 (0.73), AL: 0.69 (0.72), AP: 0.82 (0.78), DP: 0.77 (0.75), PB: 0.78 (0.78) and in the septal segment (LAO-projection): 0.69 (0.71). Less sufficient correlations were found in the posterolateral segment (LAO, especially at rest: 0.50 (0.69). Thus, global ventricular parameters can be determined at rest and during exercise independently of the observer. Local wall motion, too, can be quantified with sufficient accuracy with exception of the posterolateral area in the LAO-projektion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01876169
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Doppler measurement of cardiac output across prosthetic mitral valves (1990)
    Springer
    Journal of molecular medicine 68 (1990), S. 263-268 
    Details
    ISSN: 1432-1440
    Keywords: Flow volume measurement ; Prosthetic mitral valve ; Doppler echocardiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In 46 patients with a normal functioning mitral valve prosthesis (15 St. Jude, 19 Medtronic Hall, 12 Hancock) cardiac output was measured by pulsed Doppler echocardiography across the valve prosthesis. Simultaneously cardiac output was determined by thermodilution or pulsed Doppler echocardiography in the left ventricular outflow tract (2.8 l/min–9.5 l/min). The prosthetic valve area was calculated using the pressure half-time method. Cardiac output was calculated by multiplying time-velocity integrals with the mitral valve area. Cardiac output measurements across the mitral prosthesis correlated significantly with thermodilution (r=0.96, SEE=0.400 l/min) and pulsed Doppler echocardiography flow measurements in the left ventricular outflow tract (r=0.82, SEE=0.679 l/min). The mean percent error of the Doppler transmitral flow measurement was 10.8%. Doppler transmitral flow underestimated cardiac output values of more than 6.5 l/min in 6 of 7 patients. Cardiac output measurements across Hancock (SEE=0.473 l/min) and St. Jude prostheses (SEE=0.538 l/min) were more accurate than across Medtronic Hall prostheses (SEE=0.847 l/ min). Cardiac output can be calculated by pulsed Doppler echocardiography across normal functioning mitral prostheses. Due to the different flow dynamics the accuracy of cardiac output measurement depends on the prosthetic valve type. Reliable measurements of cardiac output can be performed across Hancock and St. Jude prostheses only. This method is limited in volume flow measurements across Medtronic Hall prostheses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02116054
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Value of a modified continuity equation method to quantify mitral valve area in patients with mitral stenosis and sinus rhythm (1991)
    Springer
    Journal of molecular medicine 69 (1991), S. 924-929 
    Details
    ISSN: 1432-1440
    Keywords: Mitral stenosis ; Mitral valve area ; Continuous wave Doppler ; Continuity equation method ; Pressure half-time method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To quantify valve area in mitral stenosis, a modified continuity equation method using continuous wave Doppler and thermodilution measurements was applied. In 14 patients with mitral stenosis and sinus rhythm (age: 49±11 years), transmitral flow velocity was recorded by continuous wave Doppler during right and left heart catheterization. Mitral valve area was calculated by three different methods: 1. According to the continuity equation, stroke volume (thermodilution technique) was divided by the registered time velocity integral of the mitral stenotic jet (continuous wave Doppler). 2. Mitral valve area was calculated by the pressure half-time method. 3. Simultaneous pulmonary capillary wedge and left ventricular pressure measurements were used for determination of mitral valve area according to the Gorlin formula. The mitral valve area determined by application of the continuity equation (y) showed a close correlation to the valve area calculated by the Gorlin equation (x):y=0.73x+0.12, SEE=0.11 cm2,r=0.88,P〈0.001. In contrast, the correlation between mitral valve area determined by pressure half-time (y) and the Gorlin formula (x) was not as good:y=0.77x+0.11, SEE=0.26 cm2,r=0.65,P〈0.05. Thus, the continuity equation method using combined continuous wave Doppler and thermodilution technique allows a valid determination of mitral valve area. In patients with mitral stenosis and sinus rhythm, this technique is superior to the noninvasive determination of mitral valve area by the conventional pressure half-time method.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01798541
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Die Doppler-echokardiographische Quantifizierung des regurgitierenden Blutvolumens bei Patienten mit Mitralinsuffizienz (1989)
    Springer
    Journal of molecular medicine 67 (1989), S. 940-945 
    Details
    ISSN: 1432-1440
    Keywords: Mitral regurgitation ; Doppler echocardiography ; Regurgitant fraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The purpose of this study was to assess the accuracy and clinical utility of pulsed Doppler echocardiography in determining the regurgitant fraction in patients with pure mitral regurgitation. In 30 unselected consecutive patients with mitral regurgitation and in 20 patients without valvular heart disease pulsed Doppler echocardiography was performed to measure blood flow at the mitral and aortic valve. The regurgitant blood volume was calculated as the difference of the stroke volumes measured at the mitral and aortic valve. The regurgitant fraction was computed as regurgitant blood volume/mitral flow. By cardiac catheterization regurgitant blood volume and regurgitant fraction were obtained from the left ventricular angiographic stroke volume and the stroke volume measured by thermodilution. Five patients were excluded because of technically poor left ventricular angiograms. In 4 patients with mitral regurgitation measurement of the regurgitant blood volume and regurgitant fraction was impossible by Doppler because of poor ultrasound signal quality. In 21 patients with mitral regurgitation the correlations between the invasive and the Doppler measurements were significant (regurgitant blood volume:r=0.89, SEE=20.9 ml; regurgitant fraction:r=0.91, SEE=7.1%). However, the mean percent error of the regurgitant fraction measurement (12.0±11.6%) was smaller than of the regurgitant blood volume measurement (24.9±17.0%). In the control group the regurgitant blood volume ranged between −25.1 ml and 11.6 ml and the regurgitant fraction between −17.7% and 12.4%. Thus, pulsed Doppler echocardiography is clinically useful in determination of the regurgitant fraction in 84% of unselected adult patients with pure mitral regurgitation. The Doppler method is limited in the diagnosis and quantification of mild regurgitation. However, the method is more accurate in determining the regurgitant fraction than measuring the regurgitant blood volume.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01721421
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Wertigkeit der 2-D-Echokardiographie zur Erkennung belastungsinduzierter Wandbewegungsstörungen bei koronarer Herzerkrankung — Ein Vergleich mit der biplanen Cineventrikulographie (1988)
    Springer
    Journal of molecular medicine 66 (1988), S. 12-20 
    Details
    ISSN: 1432-1440
    Keywords: Exercise-echocardiography ; Exercise-cineventriculography ; Exercise induced myocardial ischemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To determine the accuracy of echocardiography in assessment of exercise-induced wall motion abnormalities, the results of stress-echocardiography were compared with exercise-cineventriculography. In 56 consecutive patients biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echocardiography was obtained using the apical 2- and 4-chamber view for LV imaging under identical exercise conditions. In 6 of the 56 patients 2-D echo, in 8 patients LV-angio, and in 2 patients both methods were of inadequate quality during exercise. Thus, in 40 patients (34 patients had coronary artery disease) local wall motion of 360 wall segments was analysed. 49 segments (14%) of 24 patients showed exercise-induced ischemic wall motion abnormalities during cineventriculography. Only 24 of these 49 asynergics (49%) were also detected by 2-D-echo. Using cross-sectional echocardiography, ischemia related wall motion abnormalities were best detected lateraly and septaly, whereas apical asynergies were identified in 3 of 12 segments only. Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected to have coronary artery disease is limited and restricted to patients with excellent visualization of the left ventricular endocardium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01735207
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Acute vessel closure following excimer laser coronary angioplasty: can we predict it? (1993)
    Springer
    Journal of molecular medicine 71 (1993), S. 978-984 
    Details
    ISSN: 1432-1440
    Keywords: Percutaneous transluminal coronary angioplasty ; Laser angioplasty ; Coronary artery disease ; Morphology ; Acute coronary artery occlusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Of 124 consecutive patients undergoing elective excimer laser coronary angioplasty, 33 (26%) had periprocedural occlusion following excimer laser irradiation. Successful management (reopened vessel, no death, no myocardial infarction, no emergency bypass surgery) including repeat lasing, subsequent percutaneous transluminal coronary angioplasty, use of intracoronary nitroglycerin or streptokinase was achieved in 32 of the patients with acute occlusion following excimer laser coronary angioplasty. In one patient a nonfatal anterior myocardial infarction occurred. A late event occurred in two patients despite patency at the control angiography 24 h later. Multiple logistic regression modeling was used to examine the relationship between various characteristics and the risk of acute vessel closure. The preprocedural and procedural variables analyzed included progressive spasm prior to occlusion and lesion morphology after intervention (angiography complications after percutaneous transluminal coronary angioplasty were prospectively divided into class 0, no complication, and classes 1–3, according to purely descriptive morphological characteristics). These showed a multivariate correlation with acute occlusion during excimer laser coronary angioplasty. These results suggest that acute vessel closure during stand-alone excimer laser coronary angioplasty is a benign but unpredictable event.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00180027
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Effect of chronic nicotine delivery on the proliferation rate of endothelial and smooth muscle cells in experimentally induced vascular wall plaques (1994)
    Springer
    Journal of molecular medicine 72 (1994), S. 908-912 
    Details
    ISSN: 1432-1440
    Keywords: Nicotine ; Smooth muscle cell ; Endothelial cell ; Atherosclerosis ; Hypercholesterolemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To study the effect of nicotine, cholesterol feeding, and their combination on endothelial and smooth muscle cells in vascular wall plaques an experimental method was established which allows the immunohistochemical detection and quantification of the fractions of endothelial and smooth muscle cells in DNA synthesis under the effect of these stimuli. For this purpose standardized fibromuscular plaques were produced by electrostimulation in the common carotid arteries of rabbits. The animals received either nicotine via implanted osmotic minipumps or a cholesterol diet or both. Plaque size was determined at the end of the experiments after 7 or 14 days as well as the fraction of endothelial and smooth muscle cells in DNA synthesis during exposure to bromodeoxyuridine (BrdU). The BrdU labeling index of endothelial cells clearly increased under chronic nicotine administration for either 7 days or 14 days compared to controls. The combination of nicotine and cholesterol diet led to a more significant increase. In contrast, the BrdU labeling index of smooth muscle cells was not increased under nicotine delivery. The combination of nicotine and cholesterol, however, led to a significant increase of the BrdU labeling index of smooth muscle cells in the plaques compared to cholesterol feeding. Measurement of the plaque size revealed no difference between controls and nicotine-treated animals after 14 days of nicotine delivery, whereas the combination of cholesterol and nicotine produced increased plaque formation compared to a group of animals which received a cholesterol diet alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190750
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Determination of right ventricular ejection fraction by thermodilution technique — a comparison to biplane cineventriculography (1988)
    Springer
    Intensive care medicine 14 (1988), S. 461-466 
    Details
    ISSN: 1432-1238
    Keywords: Right ventricle ; Ejection fraction ; Thermodilution method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Determination of right ventricular ejection fraction (RVEF) provides information about global right ventricular function, which may be important for the management of patients with various heart diseases. Right ventricular ejection fraction can be determined by new thermodilution techniques using fastresponse thermistors. To evaluate the validity of these methods, thermodilution measurements were compared with biplane cineventriculography in 22 patients undergoing cardiac catheterization. In all patients standard deviation of RVEF was below 5%. Mean RVEF, determined by thermodilution, was 52%±9%, ranging from 32% to 71% and correlated significantly with the results of angiography (RVEF: 52%±9%) (r=0.80, SEE±5%, n=22, p〉0.001). Correlation was good especially in patients with small right ventricles (〉60ml) (r=0.91, SEE±5%, n=13, p〉0.001), lower heart rates (〉65/min) (r=0.84, SEE=±6%, n=12, p〉0.001) and cardiac output below 5.5 l/min (r=0.88, SEE±6%, n=11, p〉0.001). Thus, if valid catheter placement is possible, right ventricular ejection fraction can be determined by thermodilution technique with good reproducibility and sufficient accuracy compared to biplane angio. Validation of this method in larger patient populations with various heart diseases is necessary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00256960
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Changes in haemodynamics and left ventricular function during intravenous nifedipine infusion with and without additional propranolol in patients with coronary artery disease. A randomized, placebo controlled trial (1987)
    Springer
    European journal of clinical pharmacology 33 (1987), S. 345-348 
    Details
    ISSN: 1432-1041
    Keywords: nifedipine ; propranolol ; calcium channel blockers ; beta-adrenoceptor blockers ; coronary artery disease
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The haemodynamic effects of a combined intravenous treatment of nifedipine and propranolol in ten patients with coronary artery disease compared to a single treatment with nifedipine or placebo were investigated. Nifedipine infusion resulted in a reduction of left ventricular (LV) afterload and LV volumes with an increase in heart rate and EF and no change of the double product, coronary sinus flow, LV diastolic parameters and dp/dtmax. Addition of propranolol lowers myocardial oxygen demand by reducing heart rate and dp/dtmax together with a sustained afterload reduction with no change in LV volumes and EF. The vasodilatatory action of nifedipine pretreatment balanced the negative effects of acute beta-receptor blockade on LV function and allows the reduction of myocardial oxygen demand without a deterioration of LV function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00637628
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...