Influence of strong static magnetic fields on heart muscle contraction

The aim of the present study was to investigate, in isolated electrically stimulated heart muscle preparations, the effect of strong static magnetic fields (B=2.11 T), in the range of the recommended upper limits in NMR tomography, on myocardial contractility, and on stimulation threshold. Since the morphology and contraction of the muscles exhibit preferential orientation, it seemed appropriate to carry out the investigations both in parallel and in vertical orientation of the muscle strips with respect to the magnetic field. The results showed that a static magnetic field of 2.1 T has no acute effects on the contractility of normoxic and hypoxic rat myocardium. (U.K.)