The Effect of the Frequency Response of Electrocardiographs on the Form of Electrocardiograms and Vectorcardiograms

The spectrum of frequencies making up the cardiac potential has not been fully explored. Limitation in the high frequency response of most electrocardiographs suppresses in some tracings QRS components whose significance is at present obscure. Using the cathode ray oscillograph it was found that frequencies as high as 1300 cycles per second reveal characteristics not shown at lower frequencies. Frequencies as high as 6400 cycles per second are under investigation. Limitation of the low frequency response by the use of a condenser-resistor network to abolish extraneous potentials produces serious distortions of the RS-T segment.