Of the various cardiac irregularities produced experimentally by digitalis, the earliest to appear in most instances is an occasional omission of ventricular contractions, owing to an interruption of the stimulus between the auricles and ventricles. Somewhat later, or even immediately after this, the heart may assume a most peculiar rhythm in which the auricles and ventricles are beating quite independently of each other.1,2 This irregularity differs from the ordinary rhythm of complete heart-block in that the ventricular rate is not slow, but approaches and, indeed, usually exceeds the auricular rate; so that, for example, one may count sixteen ventricular to fifteen auricular contractions. This rhythm is so common in carefully graded digitalis poisoning in dogs that it has become a regular portion of the pharmacologic demonstrations given by Dr. Edmonds to the University of Michigan students and by Professor Hatcher to the Cornell University students. So
HEWLETT AW, BARRINGER TB. THE EFFECT OF DIGITALIS ON THE VENTRICULAR RATE IN MAN. Arch Intern Med (Chic). 1910;V(2):93–101. doi:10.1001/archinte.1910.00050240002001
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