caa a22 4500 465785794 CHVBK 20180323112008.0 cr unu---uuuuu 170327e19900401xx s 000 0 eng 10.1007/BF00842775 doi (NATIONALLICENCE)springer-10.1007/BF00842775 The effects of microsphere injections into the left atrium on the myocardial blood supply measured by thermal conductance probes [Elektronische Daten] [Norbert Hahn, Wolfgang Eichelkraut, Joachim Kropp] Former experiments with thermal conduction probes showed signs of reductions or increases of myocardial perfusion shortly after injection of microspheres into the left atrium. Because of this, 210 measurements made during experiments on 66 dogs under propionylpromazine/pentobarbital narcosis were newly analysed to verify a possible influence of microspheres (9 μm 0) injected into the left atrium on microcirculation. Using 20 additional dogs in identically performed experiments, the myocardial perfusion was measured using thermal conductance probes, following injections of isotonic NaCl solution (8 ml each), Ringer's solution, 5% glucose, the subject's blood, and isotonic NaCl solution mixed with the surface-active substance Tween 80®. These suspension media were injected both with and without unlabelled microspheres (8.6 μlm Q1). The results led to the following conclusions: An obligatory decrease in the blood supply as the result of a mechanical blocking of capillaries by microspheres can be ruled out. The particles, the suspension media, and a suspension temperature not sufficiently adjusted to the body temperature induce reactive negative or positive changes in the microcirculation of the myocardium. This was found in approx. 45%-75% of cases. Solutions containing particles cause, in the majority of cases, a decrease. The suspension medium with the smallest effect proved to be isotonic NaCl solution. From the results one can conclude that artefacts may arise from the application of the heat conductance probe method when the temperatures are not perfectly matched. However, the injected solution itself can often lead to various reactions in microcirculation which may last up to 5 min. It is advisable to allow at least 6 min to elapse after reactive changes have faded before administering the next injection. In no case could the effects observed using the thermal conductance probes be confirmed by another measurement parameter (ECG, heart frequency, left ventricular pressure, dp/dtmax, aortic pressure). Springer-Verlag, 1990 Myocardium nationallicence Perfusion nationallicence Effects of microspheres nationallicence Thermal conductance probes nationallicence Hahn Norbert Experimental Surgery, Surgical Clinic, and Department of Nuclear Medicine, University of Bonn, Germany aut Eichelkraut Wolfgang Experimental Surgery, Surgical Clinic, and Department of Nuclear Medicine, University of Bonn, Germany aut Kropp Joachim Experimental Surgery, Surgical Clinic, and Department of Nuclear Medicine, University of Bonn, Germany aut European Journal of Nuclear Medicine Springer-Verlag 16/4-6(1990-04-01), 241-247 0340-6997 16:4-6<241 1990 16 259 https://doi.org/10.1007/BF00842775 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00842775 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hahn Norbert Experimental Surgery, Surgical Clinic, and Department of Nuclear Medicine, University of Bonn, Germany aut NATIONALLICENCE 700 1- Eichelkraut Wolfgang Experimental Surgery, Surgical Clinic, and Department of Nuclear Medicine, University of Bonn, Germany aut NATIONALLICENCE 700 1- Kropp Joachim Experimental Surgery, Surgical Clinic, and Department of Nuclear Medicine, University of Bonn, Germany aut NATIONALLICENCE 773 0- European Journal of Nuclear Medicine Springer-Verlag 16/4-6(1990-04-01), 241-247 0340-6997 16:4-6<241 1990 16 259 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer