[Electrocardiograms of digitalis intoxication. Reevaluation]

Serum digoxin concentration and ECG were recorded 111 times in 96 patients taking digoxin. The generally accepted ECG criteria of digoxin concentration seem greatly to overestimate the incidence of toxic cases. According to these criteria 63 ECGs in this study would have been regarded as toxic, whereas toxicity (defined by the association of serum digoxin elevation and clinical symptoms of toxicity) was actually present in only 11 cases.