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  • General Chemistry  (3)
  • heart failure  (3)
  • AV-Überleitungsstörungen  (1)
  • Acute myocardial infarction  (1)
  • 1
    ISSN: 1435-1803
    Keywords: atrial natriuretic peptide ; heart failure ; regionalblood flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To characterize the systemic and regional vascular effects of atrial natriuretic peptide (ANP) in chronic heart failure, central hemodynamics, regional blood flow and plasma ANP levels were determined in a rat model of myocardial infarction and failure and in sham-operated animals. Measurements were made in the conscious state before and after intravenous rANP [99-126] (8 μg bolus followed by continuous infusion of 1.0 μg/kg/min). With this protocol, ANP significantly decreased cardiac output, right atrial, left ventricular enddiastolic and arterial pressures and there were increases in heart rate, systemic and intestinal vascular resistances in sham animals. Renal blood flow per gram of tissue was unchanged with ANP, but when expressed as a percentage of cardiac output, increased significantly, indicating a preferential renal vasodilatory effect of ANP. In rats with infarction and failure, this dose did not alter cardiac output or arterial pressure, but decreased right atrial and left ventricular blood flow. Although significantly reduced as compared to the control group, renal blood flow was not improved with ANP in the heart failure group. ANP plasma levels of the heart failure group were elevated at baseline (p〈0.01), and increased 5–10 times after infusion of rANP. Thus, in rats with chronic heart failure, the renal vascular effects of ANP are blunted, which may, in part, explain the failure of ANP to restore the altered volume homeostasis in heart failure despite elevated ANP plasma levels. However, the effects on venous return were preserved which, in turn, improved cardiac performance via a reduction of preload.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Intensive care medicine 2 (1976), S. 7-11 
    ISSN: 1432-1238
    Keywords: Left ventricular function ; Wall stiffness and contractility ; Acute myocardial infarction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 10 patients with their first AMI were studied within the first 48 hours and again after 3 weeks. Central and peripheral haemodynamics (CI, SV, SW, TPR) were examined, including indices of contractility (dp/dlmax) and wall stiffness (ΔP/ΔV, relation ΔP/ΔV to P) of the left ventricle. In the early phase CI and SW, as well as LV dp/dtmax were depressed in accordance with symptoms of LV failure. ΔP/ΔV was increased. Elevation of LVEDP correlated well with ventricular gallop rhythm, but less consistently with LV functional disturbance. During convalescence CI increased uniformly, both in digitalized and non-digitalized individuals. In contrast heart rate, aortic pressure, LVEDP and dp/dtmax remained unchanged. The increase of CI, SV and SW was accompanied by a fall of TPR and ΔP/ΔV. LV wall stiffness was still elevated above normal after 3 weeks. The improvement of cardiac pumping during infarct convalescence may have been effected through a fall of TPR and LV wall stiffness. Recovery of depressed contractile performance was generally not observed, and does therefore not seem to contribute to recuperation.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 51 (1973), S. 791-800 
    ISSN: 1432-1440
    Keywords: Fascicular block ; mono- ; bi- ; trifascicular block ; hemi block ; av-conduction disturbances ; HIS bundle-ECG ; Fasciculärer Block ; mono- ; bi- ; trifasciculärer Block ; Hemiblock ; AV-Überleitungsstörungen ; His-Bündel-EKG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Auf Grund experimenteller und klinischer Beobachtungen können im AV-Überleitungssystem distal vom Hisschen Bündel 3 verschiedene Leitungsbahnen unterschieden werden. Eine genauere Lokalisierung der Unterbrechung einer oder mehrerer Bahnen ist durch eine auf Grund der Blockierung hervorgerufene Änderung des EKG's in Verbindung mit Registrierung der elektrischen Potentiale des Hisschen Bündels möglich. In Anlehnung an die Klassifizierung von Rosenbaumet al. (1970b) werden folgende Blockierungen bzw. Verzögerungen der Erregungs-Leitung unterschieden: 1. Unterbrechung der Leitung vor Aufteilung des Leitungs-systems in die drei distalen Bahnen in Form eines monofasciculären Blocks im Bereich der Pars penetrans des Hisschen Bündels unter dem Bild eines kompletten AV-Blocks. 2. Unterbrechung nach Aufteilung in die distalen Bahnen als monofasciculärer Block in Form eines Rechtsschenkelblocks (RSB), Linksschenkelblocks (LSB), linksanteriorern Hemiblocks (LAH) und linksposterioren Hemiblocks (LPH), 3. als bifasciculärer Block in Form eines RSB alternierend mit einem LSB, RSB mit LAH oder RSB mit LPH, bzw. eines permanenten Blocks in einem Faszikel mit Verlangsamung der Erregungsleitung im kontralateralen Schenkel (LSB mit Verzögerung der Überleitung im rechten Schenkel), 4. als trifasciculärer Block z. B. bei intermittierendem Befall aller 3 distalen Bahnen entweder in Form eines RSB mit LAH im Wechsel mit RSB mit LPH, RSB mit LAH im Wechsel mit komplettem LSB, bzw. kompletter Unterbrechung zweier Faszikel mit Leitungsstörung im verbleibenden dritten distalen Ast (RSB mit LAH mit Verzögerung der Leitung im linksposterioren Ast), oder permanenter Unterbrechung aller drei distalen Bahnen (subdivisionaler AV-Block 3. Grades). Die Genese der Blockformen und die prognostische Bedeutung bei unvollständiger Blockierung hinsichtlich der Entwicklung eines vollständigen ASV-Blocks werden an Hand der Literatur und eigenen Untersuchungsergebnissen diskutiert. Dabei ist die Häufigkeit vorangegangener fasciculärer Blockierungen bei Patienten mit permanentem komplettem AV-Block auffällig, ebenso wie der komplette Block distal vom Hisschen Bündel bei Patienten mit chronischem AV-Block 3. Grades. Bemerkenswert ist auch das nicht seltene Zusammentreffen von Leitungsstörungen sowohl proximal als distal vom Hisschen Bündel beim gleichen Patienten.
    Notes: Summary Experimental and clinical studies have demonstrated that the av-conduction system distal to the bundle of His can be divided into 3 distinct fascicles. The recording of electrical potentials of the bundle of His permits to determine the location of a conduction disturbance in connection with changes produced by the block of one or more of the fascicles. According to the classification of Rosenbaumet al. (1970b), the following conduction disturbances can be distinguished: 1) block in the penetrating portion fo the bundle of His, producing a monofascicular block in the form of a complete av-block. 2) monofascicular block distal to the common av-bundle as right bundle branch block (RBBB), left bundle branch block (LBBB), left anterior hemi-block (LAH) or left posterior hemi block (LPH), 3) bifascicular block as RBBB alternating with LBBB, RBBB with LAH, RBBB with LPH, or monofascicular block with impairment of conduction in the contralateral fascicle (LBBB with conduction disturbance in the RBB), 4) trifascicular block, i.e. intermittent block in all 3 terminal fascicles as RBBB with LAH changing to RBBB with LPH or RBBB with LAH changing to complete LBBB, or bifascicular block with conduction disturbance in the remaining distal tract (RBBB with LAH with impaired conduction in the remaining posterior fascicle) or permanent block of all 3 fascicles (subdivisional 3rd degree av-block). The aetiology and prognostic significance of the different forms of fascicular block especially in regard to the development of complete av-block are discussed. The high percentage of fascicular block as precursor of complete block is emphasized as well as the high percentage of blocks distal to the bundle of His in patients with chronic complete av-block. His bundle recordings can also demonstrate that block both proximal and distal to the common av-bundle in the same patient is not unusual.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Basic research in cardiology 92 (1997), S. 87-93 
    ISSN: 1435-1803
    Keywords: Calcium ; heart failure ; sarcoplasmic reticulum ; geneexpression ; human myocardium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract There is accumulating evidence that disturbed calcium homeostasis may play a key role in the pathophysiology of human heart failure. Because disturbed calcium handling could result from altered protein expression, levels of calcium handling proteins were quantitated by Western Blot analysis in failing and nonfailing human myocardium from hearts with endstage failing dilated or ischemic cardiomyopathy. Protein levels of the sarcoplasmic reticulum calcium release channel (ryanodine receptor) and of calcium storage proteins (calsequestrin and calreticulin) were similar in failing and nonfailing human myocardium. However, proteins involved in calcium removal from the cytosol were significantly altered in the failing human heart: 1) SR-Ca2+-ATPase, relevant for removal of calcium from the cytosol into the lumen of the sarcoplasmic reticulum, was decreased; 2) phospholamban, which inhibits the SR-Ca2+-ATPase in the basal unphosphorylated state, was slightly decreased; 3) the ratio of SR-Ca2+-ATPase to phospholamban was decreased; 4) the sarcolemmal Na+−Ca2+-exchanger, relevant for transsarcolemmal calcium extrusion was increased in the failing hearts. In summary, altered levels of proteins involved in calcium removal from the cytosol suggest an increase in transsarcolemmal calcium elimination relative to sarcoplasmic reticulum calcium removal. These findings support the concept that reduced function of the sarcoplasmic reticulum to accumulate calcium may reflect a major defect in excitationcontraction coupling in human heart failure.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Basic research in cardiology 91 (1996), S. 17-22 
    ISSN: 1435-1803
    Keywords: Excitation-contraction coupling ; heart failure ; force-frequency relation ; calcium cycling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Myocardial function, intracellular calcium and levels of calcium cycling proteins were analyzed in failing and nonfailing human myocardium. Myocardial function was evaluated by the isometric force-frequency relation, and intracellular calcium was studied by aequorin light emission. When stimulation frequency was increased above 30 min−1, there was a continuous increase in isometric tension development in the nonfailing myocardium. In contrast, in failing myocardium, frequency potentiation of contractile force was blunted or inverse. As a consequence, at higher rates of stimulation, twitch tension was reduced significantly in failing compared to nonfailing human myocardium. Aequorin measurements indicated that the contractile deficit in the failing myocardium at higher rates of stimulation is associated with decreased free intracellular calcium concentration. Western blot analysis indicated that in the failing myocardium protein levels of SR-Ca2+-ATPase are significantly reduced and protein levels of Na+−Ca2+-exchanger are significantly increased. Levels of phospholamban are slightly reduced in the failing myocardium, and ryanodine receptor and calsequestrin protein levels are unchanged. There was a close positive correlation between the protein levels of SR-Ca2+-ATPase and frequency potentiation of contractile force. From these data, we conclude that in failing compared to nonfailing human myocardium 1) force-frequency relation is blunted or inverse. 2) Frequency-dependence of contractile force is closely correlated with frequency-dependence of intracellular calcium cycling. 3) Protein levels of SR-Ca2+-ATPase may determine frequency-dependence of sarcoplasmic reticulum calcium release. 4) Calcium elimination by an increased number of Na+−Ca2+-exchanger molecules may be a compensatory mechanism to prevent diastolic calcium accumulation in failing myocardium with a reduced number of SR calcium pumps.
    Type of Medium: Electronic Resource
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  • 6
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 42 (1929), S. 984-987 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 9 Tab.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 42 (1929), S. 1002-1007 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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