[ECG changes caused by the effect of static magnetic fields of nuclear magnetic resonance tomography using magnets with a field power of 0.5 to 4.0 Telsa].

ECG-alterations under the influence of static magnetic fields were investigated in phantoms (1.5 Tesla), animals and volunteers (4.0 Tesla), as well as in 12 patients (0.5, 1.0, and 1.5 Tesla). Under the influence of static magnetic fields high- and low-frequency voltages are superimposed on the ECG. Motions of the electrical leads induce high-frequency waves, which can alter the ECG to the extent that only the QRS-complex can be recognized. Electrolytes moved by the blood stream in static magnetic fields also induce voltages (Hall-effect) which, according to the patient's position, result in ST-segment- and partial T-wave-elevations or depressions. All ECG-alterations are reversible after exposition to the static magnetic field. Rhythm disturbances do not occur. The results indicate that static magnetic fields up to 4.0 Tesla do not have permanent adverse effects on the human ECG.