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  • 1
    ISSN: 1432-1440
    Schlagwort(e): Regional left ventricular function ; Aortocoronary bypass surgery ; Regionale linksventrikuläre Funktion ; Aorto-koronarer Bypass
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Bei 20 konsekutiven Patienten (mittleres Alter 51,6 Jahre) mit der Diagnose einer stabilen, schweren Angina pectoris wurden aortocoronare Bypass-Operationen durchgeführt und insgesamt 60 Anastomosen gefertigt. First-pass Radionuclid Ventrikulogramme (18–24 mCi 99m Technetium Pertechnetat i.v.) erfolgten sowohl in Ruhe als auch nach maximaler Belastung im Durchschnitt 9,4±1,5 Monate postoperativ. Neben der globalen Ejektionsfraktion (GEF) wurde die regionale Ejektionsfraktion (REF) gemessen. Die REF wurde neu definiert und mit einer speziellen Technik erarbeitet: Jedes postoperative Radionuklid-Ventrikulogramm (RAO-Ansicht) wurde in drei Regionen unterteilt, entsprechend dem Versorgungsgebiet der drei Hauptkoronararterien und ihrer Äste. Die Größe und die Verzweigung der Koronararterien wurden auf dem präoperativen Kontrastmittel-Koronarangiogramm eingesehen. Die GEF verbesserte sich nach maximaler Belastung in 13 Fällen um 8,1%-Einheiten (von 50,5 auf 58,5%), blieb unverändert 3mal und verschlechterte sich 4mal um 7,1%-Einheiten (von 51,6 auf 44,5%; alle Änderungenp〈0,05). In komplett revaskularisierten Regionen (n=33) verbesserte sich die REF 24mal um 9,7%-Einheiten (von 51,1 auf 60,8%). Die Belastungs-REF änderte sich nicht wesentlich von der Ruhe-REF 6mal; in drei Fällen konnte eine Verschlechterung um 7,3%-Einheiten gemessen werden (von 48,6 auf 41,3%; alle Veränderungenp〈0,05). Komplett revaskularisierte Regionen reagierten auf Belastung wie normal perfundierte Gebiete (Anstieg um 7,8%-Einheiten; von 50,6 auf 58,4%n=7;p〈0.05). Die REF verschlechterte sich in inkomplett revaskularisierten Gebieten (n=9) 6mal um 12,8%-Einheiten (von 58,0 auf 45,2%), blieb unverändert 2mal und verbesserte sich 1mal um 4.5%-Einheiten. Die REF der Gesamtgruppe verschlechterte sich um 7,3%-Einheiten (von 56,8 auf 49,5%;p〈0,05). Die Belastungs-REF der inkomplett revaskularisierten Regionen war hoch signifikant schlechter als diejenigen der komplett revaskularisierten Regionen (49,5 gegenüber 58,4%;p〈0,01). Die GEF ist eine gewichtete Bilanz aller dreier Ejektionsfraktionen. Der wichtigste Parameter ist die REF des Ramus interventricularis anterior-Gebietes.
    Notizen: Summary Twenty consecutive patients (mean age 51.6 years) with persistent severe angina pectoris underwent aorto-coronary bypass surgery receiving an overall of 60 anastomosis. On an average, 9.4±1.5 months p.o. first pass radionuclide ventriculograms (18 to 24 mCi 99 m Technetium-Pertechnetate i.v.) were performed at rest and after excerise. Besides measurement of global ejection fraction (GEF), regional ejection fraction (REF) was assessed employing for the first time a new technique: each RAO-view of p.o. radionuclide left ventriculogram was subdivided into three regions according to supply of the three main coronary arteries and their branches as visualized on pre-operative coronary angiogram. GEF improved after maximum exercise in 13 cases by 8.1% points (from 50.4 to 58.5%), remained unchanged three times and decreased four times by 7.1 points (from 51.6 to 44.5%; all changesp〈0.05). In completely revascularized regions (n=35) REF improved 24 times by 9.7 points (from 51.1 to 60.8%), did not differ from rest REF six times and decreased in three case by 7.3 points (from 48.6 to 41.3%; all changesp〈0.05). Completely revascularized regions responded to exercise like normally perfused areas (increase 7.8 points (from 50.6 to 58.4%;n=7;p〈0.05). REF deteriorated in incompletely revascularized regions (n=9) six times by 12.8 points (from 58.0 to 45.2%), remained unchanged twice and improved once by 4.5 points. Total group's REF decreased by 7.3 points (from 56.8 to 49.5%;p〈0.05). Exercise REF of incompletely revascularized regions was highly significant inferior to that of completely revascularized regions (49.5 to 58.4%;p〈0.01). GEF is a weighted balance of the three regional ejection fractions. The most important parameter is REF of LAD territory.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1432-2277
    Schlagwort(e): Key words Transplantation ; Nitric oxide ; Endothelial function ; Gene expression ; Cytokines
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Endothelial dysfunction anticipates the development of transplant coronary artery disease (TxCAD) observed more than 1 year after transplantation (HTx). We investigated whether in patients early after HTx myocardial inducible and constitutive nitric oxide synthases (iNOS; cNOS) are expressed and cardiac nitric oxide production occurs. Moreover, a possible relationship to alterations in endothelium dependent and independent vasomotor function was assessed. Forty-two transplant recipients were studied 37 ± 5 days after HTx. Microvascular coronary flow velocity reserve (CFVR) was tested endothelium dependent (acetylcholine; 30 μg/min × 5 min/i.c.) and independent (adenosine; 160 μg/min × 5 min/i.c.) by Doppler flow wire. Flow velocity increase by a factor greater than 2 was considered normal. Quantitative coronary angiography was used to assess epicardial vasomotor function in response to the same stimuli. Myocardial iNOS and cNOS gene expression were detected by semiquantitative reversed transcriptase polymerase chain reaction. Plasma nitrite levels (μM) were measured by spectrophotometry. Cytokines (TNF-a, IL-6; pg/ml) were measured by enzyme linked immunosorbent assay. In 26.1 % of patients (n = 11; group A) an impaired endothelium dependent CFVR (1.65 ± 0.23 increase) was observed; in 73.9 % (n = 31, group B) a normal endothelium dependent CFVR (3.0 ± 0.7 increase; P = 0.003) was observed. Myocardial iNOS and cNOS gene expression did not differ between the two groups. Transcardiac cytokine production was noted in 58.8 % of patients for IL-6 and in 53.3 % for TNF-α. Coronary sinus (CS) levels of TNF-α, IL-6 and nitrite were higher in group A. A significant increase in nitrite production was found only in patients with impaired endothelium dependent CFVR (aorta: 43.9 ± 3.7 vs CS: 52.8 ± 5.6, P = 0.05), suggesting transcardiac nitric oxide production. In addition, CS nitrite levels correlated with CS TNF-a levels in patients with impaired CFVR (r = 0.44, P = 0.003). Microvascular endothelium dependent CFVR is impaired in 26 % of patients early after HTx. Activation of cytokines and the NO pathway seem to be involved in this vasomotor dysfunction The association between cardiac nitric oxide production and TNF-a in this group indicates a chronic high immunologic process, which may represent an early and important target for therapy and prevention of TxCAD.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1432-2277
    Schlagwort(e): Key words Nitric oxide ; Endothelin ; Humans ; Heart transplantation ; Endothelial function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Endothelial dysfunction precedes and predicts transplant vasculopathy. We investigated the relationship between endothelial dysfunction and the vasoactive mediators nitric oxide and endothelin, 33.7 ± 2.0 days after heart transplantation. Coronary flow was measured in 18 patients to determine the endothelial microvascular vasomotor response to acetylcholine. Endomyocardial biopsies were taken to determine the levels of gene expression of isozymes of endothelin and nitric oxide synthases (NOS). Blood samples from the coronary sinus and aorta were withdrawn for measurement of endothelin, nitrite and cytokines. Five patients (30 %) showed an impaired coronary flow reserve response to acetylcholine, significantly higher inducible NOS gene expression and significant transcardiac nitrite production. Plasma nitrite correlated with tumour necrosis factor-alpha levels in coronary sinus and a transcardiac net extraction of endothelin was noted in all patients. In conclusion, 30 % of patients develop endothelial dysfunction early after heart transplantation; this correlates with the expression and activation of vasoactive and immunomodulatory mediators, which may predict the development of transplant vasculopathy.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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