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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The artificial heart is a device for urgent solution of final heart failure. The systems used currently for this task are particularly pneumatic systems that allow only a limited life comfort for the patient. Therefore they have been used for short-term application as so-called bridge systems designed for periods preceding heart transplantation. Artificial hearts should be available for such situations. They are antithrombogenic owing to their construction and material properties and thus the patient's central nervous system is not threatened by thromboembolic complications. The Czechoslovak artificial heart TNS-Brno-VII is optimal in this respect. In experiments lasting for months, however, microembolism into the CNS from a calcified diaphragm often threatens the experimental animal. This danger can be limited both by optimal construction of the pump and by affecting the calcifying mechanism biologically, or by suitable processing of the diaphragm material that prevents calcifying nucleation. Perfect technology in the production of artificial hearts warrants complete elimination of potential air embolism into the central nervous system. Therefore the aim of further research is to design an absolutely defect-free system of the artificial heart which would eliminate any damage to the central nervous system during permanent long-lasting application, either on the basis of cerebral embolism of any origin, or on the basis of CNS hypoperfusion caused by limited pumping function of the artificial heart.
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PMID:Central nervous complications in subjects with artificial heart. 232 67

A summary of the development of total artificial heart research in Czechoslovakia is presented. The experimental setting of this research was based mainly on experiments on calves and partially on goats. The original concept of the blood pump is represented by an asymmetrical type of pump with an asymmetrical diaphragm and undulating motion of the diaphragm allowing optimal washing of the blood chamber. This is the key factor of the antithrombogenic properties of the latest version of the Brno artificial heart. For the pneumatic drive of the artificial heart control and driving units of our own construction--Chirasist-TN-3--are used. In 50 completed long-term experiments the mean survival time was 117.4 days. In the group of 23 experiments with polyurethane total artificial heart (TAH) the mean survival time was 133.9 days. The longest survival was achieved in the calf "Artur", No. 121 with 293 days of pumping which is worldwide one of the three longest survival times with TAH using the calf as an experimental animal. The experiment with an intrathoracic TAH implantation in the goat with a survival time of 184 days represents a worldwide unique success. After solving a number of technical and biological problems, we focused our attention on two crucial complications, i.e. increased central venous pressure leading to severe liver damage and diaphragm calcification. The original Brno concept concerned with the pathomechanism of central venous pressure increase made efficient pathogenetic therapy feasible and resulted in a marked protection of liver functions, so that increased venous pressure is no longer a problem in our experiments that would limit the period of survival. However diaphragm calcification has remained a serious survival limiting complication and therefore prevention of calcification is in the focus od our intensive research activities. Parallelly with these activities we have been engaged in research aimed at the clinical application of the TAN to bridge the period in severely affected patients until a suitable heart transplant is available. So far we have performed four artificial heart implantations in patients in the final stage of heart failure. We could keep these four patients on the TAH from one to ten days without the slightest failure of the system, and the blood chambers of the TAH-TNS-BRNO--VII/Klin/80, removed from the patient's chest after pumping had been stopped, were completely free of thrombi.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[The contribution of artificial heart research in Czechoslovakia to modern medical science]. 276 53

These data confirm the presence of abnormal skeletal muscle metabolic function in patients with chronic heart failure. These changes are independent of patient compliance and central hemodynamic response to conventional exercise, and may explain, in part, the marked decrease in exercise tolerance often observed in patients with chronic severe heart failure. The etiology of these abnormalities of metabolic function and nutritive flow remains uncertain. TNS may prove useful in further elucidation of the peripheral metabolic consequences of chronic heart failure.
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PMID:Abnormalities of skeletal muscle metabolism during nerve stimulation determined by 31P nuclear magnetic resonance spectroscopy in severe congestive heart failure. 767 88