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LARGELY as a result of the brilliant fundamental studies of Wilson and the Ann Arbor school, the last decade has witnessed a large-scale change in electrocardiograph technics and in the thoroughness with which electrocardiograms are recorded. Whereas routine studies formerly included the three conventional bipolar extremity leads of Einthoven and a single or perhaps two "precordial" leads, likewise utilizing a bipolar technic, the recent trend, except in a few clinics, has been to include the three conventional limb leads, three unipolar limb leads and six (or in some quarters seven) unipolar chest leads. It is the current consensus, as indicated . . .
Levine et al. (Thu,) studied this question.