Supplemental value of the intracavitary electrocardiograph in cardiac catheterization

Characteristic intracavitary electrocardiographic complexes at various sites within the heart in normal individuals have been described previously. The intracardiac tracings in 150 catheterizations, 129 of which were abnormal hearts, predominantly congenital defects, were studied in relationship to the position within the heart as determined fluoroscopically. In our experience, the tracings remain sufficiently unchanged in abnormal hearts so that the intracavitary electrocardiogram may be used successfully as a guide, making it possible to decrease total x-ray exposure time considerably. In addition, the significance of an intracavitary injury current became apparent. A few diagnostically useful variants were found and are described.