Further Studies in High Fidelity Electrocardiography: Myocardial Infarction

High fidelity electrocardiography employing the cathode ray oscillograph with an expanded time scale reveals considerable high frequency notching, slurring, beading, and other peculiarities not seen in the conventional electrocardiographic records on the same individuals. Although some of these cathode ray records contain components whose frequencies are well in excess of 1000 cycles per second, in this paper a frequency analysis will not be reported but rather the electrocardiograms will be presented as patterns with unique detail that is readily apparent even to the casual observer. Using this technic it was found that 14 of 21 individuals with healed myocardial infarction had a greater incidence of obvious high frequency components in their cathode ray electrocardiograms than was found in a series of 60 normal controls. The possible significance of this finding and the need for further study are discussed.