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Biomedical subjects

H Keilbach

Publications and source records attributed to H Keilbach.

At least 19 recordsLinked to original sources

[Chronobiological aspects of artificial total heart replacement in long-term animal experiments--a systemanalytic study (author's transl)].

Biological rhythms (circadian rhythms) have been observed in the hemodynamics of experimental animals (calves). After artificial total heart replacement these rhythms are typically altered compared to control animals. These observations induce a growing consideration of chronobiological aspects in a systemanalysis for the conception of an automatic external control of the artificial heart, which has to be divided in:--parameter-progression (tendencies), --parameter-variation (discrete, oscillations), --parameter-coupling (phase shifts).

Animals↗

[Observation in 10 calves with a survival time of more than 100 hours after total heart replacement (author's transl)].

It is reported on 10 calves surviving total artificial heart replacement more than 100 hours. Pneumatically driven double-chambered blood pumps made of silastic were implanted. During the experiments an increase of the right atrial pressure as well as a rise of the perfusion volumes (CO) and of the blood volumes could be found regularly. At autopsy congestion of the organs especially of the liver was a regular finding. The changed hemodynamic is first seen as possible reason for this developments. The influence of anemia and the possible disturbances in the neurohumoral autoregulation of the animals by unphysiologic pressure curves are discussed.

Animals↗