ABNORMAL RAPID RHYTHMS ASSOCIATED WITH DIGITOXIN THERAPY

Abstract

The percentile incidence of toxic rapid rhythms was greater in a group of general hospital patients receiving digitoxin than in those receiving digitalis leaf, but the difference was not statistically significant. 7 cases of digitalis poisoning among 338 patients receiving digitoxin comprised 3 instances of idio-ventricular rhythm, 3 of paroxysmal ventricular tachycardia, and 1 of interference with dissociation. In 3 cases the dosage of digitoxin was excessive and in 3 it was not; in the 7th it may have been excessive. Due to the freedom from local toxic effects with digitoxin, these toxic rhythms may be more insidious in their onset than with digitalis leaf. A rising ventricular rate or the sudden regularization of a totally irregular rhythm may serve as clues to the imminence in the. one case, or the inception in the other, of these abnormal disturbances of rhythm.