Fifteen patients with different degrees of chronic bradyarrhythmias of supraventricular origin were studied with Holter monitoring before and during application of a transdermal patch of scopolamine. No changes were found in the mean or minimal heart rates, standard deviation of the RR interval, or the degree of bradyarrhythmia. It is concluded that transdermal scopolamine is not an adequate treatment of chronic symptomatic bradyarrhythmias.