Vectorcardiogram and Aortic Blood Flow of Squirrel Monkeys (Saimiri sciureus) in a Strong Superconductive Electromagnet
In a previous study by Beischer and Knepton,(l) wherein squirrel monkeys were exposed to magnetic fields up to 70,000 Oe, a striking increase in the T-wave amplitude of the electrocardiogram (ECG) was observed and found to be proportional to the field strength, with a value of 0.05 mV per 10,000 Oe. An influence of the magnetic field on the repolarization of the heart was advanced as a tentative interpretation of this observation. Recently, Togawa et al.(2) showed, in experiments with rabbits in a field of 10,000 Oe, that the electromotive force (emf) of blood flow was superimposed on the ECG. The emf of flow was small, but at least two peaks were observed between the S wave and the end of the T wave of the ECG. The connection of this potential with blood flow was demonstrated by reversal of the sign of the flow emf at inversion of the polarity of the magnetic field. In the present study with squirrel monkeys, the use of a superconductive magnet with high field strength and application of vectorcardiographic leads furnished much stronger and clearer signals than those of the previous studies.(1,2) The observed increase of the T wave has thus been confirmed to be a superimposition on the ECG of the emf generated by blood flow, as first suggested by Togawa. The magnetic method provides, in a single record, information on the electrical and mechanical activity of the heart and represents a new, noninvasive method of studying cardiac performance.
KeywordsMagnetic Field Aortic Valve High Magnetic Field Strong Magnetic Field Flow Signal
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