Library

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
    ISSN: 1432-1440
    Keywords: Cardiotoxicity of contrast media ; Angiocardiography ; Calcium addition to ionic contrast media ; Metrizamide ; Kardiale Nebenwirkungen von Kontrastmitteln ; Kalziumzusatz zu ionischen Kontrastmitteln ; Metrizamid ; Angiocardiographie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In einer klinischen Vergleichsstudie wurde überprüft, inwieweit die kardialen Nebenwirkungen der Angiokardiographie durch Zusatz von Kalzium zum üblicherweise verwandten Diatrizoat (Urografin 76%) und Verwendung von nichtionischem Metrizamid (Amipaque) reduziert werden können. Fünfzehn Patienten wurden hierzu unter randomisierten Bedingungen mit Diatrizoat, mit und ohne Kalziumzusatz (11,3 mmol/l), und Metrizamid (320 mg/ml Jod), in jeweils einer Untersuchung, links und rechts koronarographiert und mit Diatrizoat sowie Metrizamid zweimalig lävographiert. Im Rahmen der selektiven, links- und rechtskoronaren Injektionen bewirkt der Kalzium-Zusatz bereits eine deutliche Abschwächung der bekannten kardiodepressiven Wirkung von Diatrizoat: Der linksventrikuläre Spitzendruck fällt statt im Mittel um 30±11% (einfache Standardabweichung) um lediglich 23±12% gegenüber dem Ausgangswert ab, dP/dtmax statt um 31±15% um lediglich 20±10%. Im paarweisen Vergleich der Injektionsreaktionen mit und ohne zugesetztem Kalzium, zeigt sich der Unterschied als schwach signifikant (p〈0,05). Bei Verwendung des nichtionischen Metrizamids zeigen sich die kardiodepressiven Nebenwirkungen in noch geringerer Ausprägung. Die Druckminderung im linken Ventrikel beträgt hier nur 13±10%, die Kontraktilität fällt lediglich um 7±7% ab (bezogen auf einen mittleren Ausgangswert). Der Unterschied zu den Reaktionen unter Diatrizoat allein ist mitp〈0,001 hochsignifikant. Die unter Diatrizoat zum Teil ausgeprägte Frequenzverlangsamung zeigt sich unverändert auch bei Zusatz von Kalzium. Bei Verwendung von Metrizamid ist sie nur angedeutet. Bei der linksventrikulären Injektion zeigen sich deutliche Unterschiede in der Phase peripherer Vasodilatation. Während es hier unter Diatrizoat zu einem deutlichen Druckabfall kommt, ist dieser unter Metrizamid, dem Kontrastmittel mit wesentlich niedrigerer Osmolarität, kaum nachzuweisen (p〈0,001). Da unter Metrizamid die unerwünschten, kardialen Nebenwirkungen, wie Senkung des Perfusionsdrucks, gering sind, erweist es sich als besonders geeignet für die Untersuchung von Risikopatienten. Hinsichtlich seiner geringen Nebenwirkungsrate übertrifft es auch Diatrizoat in Kombination mit Kalzium.
    Notes: Summary Cardiodepressive side effects of angiocardiography can be reduced by using non-ionic metrizamide (Amipaque) or adding calcium to diatrizoate (Urografin 76%). In 15 patients with coronary artery disease undergoing heart catheterization, we compared cardiac side effects of coronary angiography and left ventricular angiography using metrizamide and diatrizoate with and without additional calcium (11,3 mmol/l) as contrast media under randomized conditions. In selective intracoronary injection with diatrizoate alone, peak left ventricular pressure and contractility (dP/dtmax) showed a fall of 30±11% and 31±15% (n=33 injections). Using diatrizoate with added calcium (11,3 mmol/l), the fall was only 23±12% and 20±10% respectively (n=31 injections). With metrizamide (n=32 injections) cardiac side effects are even less and the decrease in pressure and contractility only 13±10% and 7±7% respectively, which its highly significant (p〈0,001) compared with the effect of diatrizoate. The heartrate slowing, not essentially altered by calcium addition, was minimal using non-ionic metrizamide. In left ventricular angiography, the pressure fall in the late phase after injection of diatrizoate, caused by decreased peripheral vascular resistance (vasodilation), was lacking when injecting metrizamide (p〈0,001). Metrizamide has even less cardiodepressive side effects than diatrizoate with additional calcium when used in angiocardiography and seems to be suitable particularly for the evaluation of high risk patients.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 13 (1978), S. 241-245 
    ISSN: 1432-1041
    Keywords: Molsidomin ; pre- and afterload ; myocardial oxygen supply/demand ratio ; hemodynamic effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Hemodynamic changes for 30 min after intravenous administration of molsidomin 4 mg were studied in 10 patients. Pulmonary artery pressure, pulmonary wedge pressure, right atrial pressure and aortic pressure decreased significantly after 15 min, and after 30 min they were still below the control level. Heart rate increased significantly (by 15%) 15 min after injection, and after 30 min it was still 8% above the control value. Cardiac index decreased significantly from 3.37±0.12 to 2.95±0.15 l/min/m2. Peripheral and pulmonary resistance showed no significant change. Both stroke work index and minute work decreased significantly 15 min after administration of molsidomin and after 30 min both were still below the control level. The results suggest that molsidomin decreases preload without influencing afterload. By decreasing preload, molsidomin improves the oxygen supply/demand ratio of the myocardium.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 1847-1849 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1435-1285
    Keywords: Key words PTCA –¶GP IIb/IIIa antagonists –¶abrupt vessel closure ; Schlüsselwörter PTCA – GP IIb/IIIa Antagonisten –¶Akuter Gefäßverschluss
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die klinische Wirksamkeit von GP IIb/IIIa Antagonisten wurde bei präinterventioneller prophylaktischer Applikation in großen klinischen Studien nachgewiesen. Ziel dieser prospektiven Studie war es, die Wirksamkeit von Abciximab bei der Anwendung in „bail-out” Situationen zu untersuchen.¶   Methoden: Insgesamt wurden bei 104 (5,5%) der 1903 Patienten, welche im Beobachtungszeitraum in unserem Zentrum dilatiert wurden, akute oder drohende Gefäßverschlüsse beobachtet. In dieser Situation wurde Abciximab in einer Dosierung von 0,25mg/kg als Bolus, gefolgt von einer Infusion von 10μg/min über 12 Stunden appliziert. Kurz nach der Gabe des Bolus wurde eine erneute PTCA durchgeführt. Am Ende der Intervention wurde die Schleuse belassen und nach 24 Std. eine Kontrollangiographie durchgeführt.¶   Ergebnisse: Bei 100 der 104 Patienten konnte ein ausreichender (TIMI III) Fluss wiederhergestellt werden. Bei 4 Patienten war die zusätzliche Implantation eines Stents notwendig. Eine Kontrollangiographie am Folgetag zeigte in allen bis auf 2 Fälle offene Gefäße mit gutem antegraden Fluss (TIMI III). Bei 4 Patienten trat nach der Intervention ein subakuter Gefäßverschluss auf. Drei von ihnen verstarben trotz einer sofort durchgeführten Notfall-ACVB OP. Das 12 Monats Follow-up beinhaltet den klinischen Status sowie eine Kontrollangiographie des Zielgefäßes. Während des Nachbeobachtungszeitraums kam es bei 15 Patienten zu einem klinischen Ereignis (2 MI, 8 ACVB, 5 Re-PTCA).¶   Schlussfolgerung: Die Ergebnisse dieser prospektiven Studie zeigen die hohe Wirksamkeit von Abciximab in „bail-out” Situationen während oder direkt nach der PTCA. Weitere Studien sollten dieses Konzept mit dem der prophylaktischen Behandlung vergleichen.
    Notes: Summary The administration of GP IIb/IIIa antagonists has been shown to be effective in reducing myocardial infarction and cardial death when given before PTCA. This prospective study was performed to determine the efficacy of abciximab in a bail-out situation to manage threatened or acute vessel closure.¶   Methods: Acute or threatened vessel closure was observed in 104 (5.5%) out of 1903 consecutive patients treated with PTCA in our institution. Of the 104 patients 46 (44%) were treated for unstable angina (CCS IV). Abciximab was administered in bail-out situations in a dosage of 0.25mg/kg given as a bolus, which was followed by an intravenous infusion of 10μg/min over 12 hours. Repeat PTCA was performed shortly after the administration of the abciximab bolus. After the procedure, the sheathe was left in place and control angiography was carried out 24 h later.¶   Results: In 100 of the 104 patients TIMI flow III could be restored by abciximab therapy and RePTCA. In 4 patients an additional stent implantation was necessary due to persistent flow limitation. One day post PTCA, early follow-up angiography demonstrated patency of all vessels except two. In-hospital events occurred in 4 patients. Three of these patients underwent emergency CABG due to subacute vessel closure a few hours after PTCA and died during or directly after surgery. Follow-up after one year included clinical status and control angiography of the target vessel. During long-term follow-up, MACE occured in 15 patients (2 MI, 8 CABG and 5 RePTCA).¶   Conclusion: The results of this prospective trial demonstrate the efficacy of abciximab therapy in bail-out situations occurring during or early after PTCA. The use of abciximab in bail-out situations appears clinically beneficial. Further studies have to compare the efficacy of this approach with prophylactic abciximab treatment.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1435-1285
    Keywords: Key words Angioplasty – smooth muscle – paclitaxel – restenosis – taxol ; Schlüsselwörter PTCA –¶Angioplastie – Paclitaxel –¶Restenose – Taxol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Paclitaxel, eine sehr potente antiproliferative Substanz, fördert die Bildung ungewöhnlich stabiler und funktionsgestörter Mikrotubuli und verändert dadurch zelluläre Mechanismen, die letztlich zu verminderter Proliferation, Migration und Signaltransduktion führen. Paclitaxel ist lipophil, was eine rasche Aufnahme in die Zelle fördert, und hat einen langanhaltenden Effekt in der Zelle aufgrund der strukturellen Veränderung des Zytoskelettes. Diese Eigenschaften machen Paclitaxel zu einem vielversprechenden Kandidaten für die lokale Medikamentenapplikation zur Restenoseprophylaxe. In dieser Arbeit werden die in-vitro und in-vivo Ergebnisse aus unseren Forschungsarbeiten zu Paclitaxel vorgestellt. Zellkulturexperimente mit Monokulturen von humanen glatten Gefäßmuskelzellen sowie mit Co-Kulturen mit humanen Endothelzellen zeigten, daß Paclitaxel in einem Dosisbereich zwischen 1,0 und 10,0μmol/l zu einer beinahe vollständigen Wachstumshemmung, selbst nach kurzer (20 min.) Einmalapplikation führt. Nach Vergleich von 3 verschiedenen Kathetersystemen (poröser Ballon, mikroporöser Ballon und Doppelballon) wurde der Doppelballon für die in-vivo Anwendung favorisiert. Anhand von Anfärbungen des Zytoskelettes sowie elektronenoptisch gelang der Nachweis der Paclitaxelwirkung in den glatten Muskelzellen der Gefäßwand. Im Kaninchen führte lokal appliziertes Paclitaxel zu einer signifikanten Hemmung der neointimalen Proliferation und Erweiterung des Gefäßdurchmessers im Vergleich zu ballondilatierten Kontrolltieren. In Zusatzexperimenten konnte eine drastische Verringerung der vaskulären Kontraktionskraft nach Paclitaxelgabe gezeigt werden. Ähnlich eindeutige Ergebnisse fanden sich nach Stentimplantation im Schweinemodell nicht.
    Notes: Summary Paclitaxel, a potent anti-tumor agent, shifts the cytoskeleton equilibrium towards assembly of altered and extraordinarily stable microtubules. These cellular modifications lead to reduced proliferation, migration, and signal transduction. It is highly lipophilic, which promotes a rapid cellular uptake, and has a long-lasting effect in the cell due to the structural alteration of the cytoskeleton. This makes paclitaxel a promising candidate for local drug delivery intended to address the proliferative and migratory processes involved in restenosis. In this article, results of our in vitro and in vivo studies with paclitaxel are presented. Cell culture experiments with monocultures of human arterial smooth muscle cells as well as cocultures with human endothelial cells showed that paclitaxel leads to an almost complete growth inhibition within a dose range of 1.0–10.0μmol/l, even after a short (20 min) single dose application. The comparison of an active, semi-active, and passive delivery system (porous balloon, microporous balloon, and double balloon) favored the double balloon for the following in vivo experiments. Tubulin staining and electron microscopy enabled visualization of paclitaxel-induced vessel wall alterations. In the rabbit model, locally delivered paclitaxel resulted in reduced neointima formation and enlargement in vessel size; in the pig model, however, after stenting, this inhibition was not significant. Both reduced proliferation and enlargement in vessel size contribute to a preservation of vessel shape and are likely to be caused by a structural alteration of the cytoskeleton, which is also supported by vascular contraction force experiments.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1435-1803
    Keywords: Key words Atherosclerosis – extracellular matrix – HMG-CoA reductase inhibitors – smooth muscle – thrombospondin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Clinical studies have shown that treatment with 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors can stabilize atherosclerotic plaques and slow their progression. One determinant of plaque stability and size is the composition of the vascular extracellular matrix. The aim of this study was to evaluate the effects of different HMG-CoA reductase inhibitors on the expression of major components of the vascular extracellular matrix in smooth muscle cells. Cultured human vascular smooth muscle cells were incubated for 24–72 h with the HMG-CoA reductase inhibitors lovastatin (1–50 μmol/L), simvastatin (0.05–20 μmol/L), and pravastatin ( 1–100 μmol/L). RNA expression of the extracellular matrix proteins thrombospondin-1, fibronectin, collagen type I, and biglycan as well as expression of the cytokine TGF-β1 was determined by Northern blotting. Extracellular matrix protein secretion was visualized by immunofluorescence. In addition, cell proliferation and viability were measured using BrDU-ELISAs, MTT-tests, and direct cell counting. Expression of thrombospondin-1 was significantly decreased after 24 h incubations with lovastatin in concentrations as low as 1 μmol/L. Coincubation with the cholesterol precursor mevalonate completely reversed this effect. The downregulation of thrombospondin-1 expression occured in the same concentration range that also inhibited cell proliferation. In contrast, lovatatin did not affect expression of fibronectin, whereas collagen type I and biglycan expression decreased only after long incubations with high, toxic lovastatin concentrations. Simvastatin, but not the very hydrophilic compound pravastatin, had a similar effect on extracellular matrix expression as lovastatin. In summary, lovastatin and simvastatin predominantly decrease the expression of the glycoprotein thrombospondin-1, which is functionally associated with smooth muscle cell migration and proliferation. In contrast, expression of plaque-stabilizing extracellular proteins such as collagen type I and biglycan are much less affected.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...