Deslanoside (Desacetyllanatoside C) is a rapidly acting cardiac glycoside used to treat congestive heart failure and supraventricular arrhythmias due to reentry mechanisms, and to control ventricular rate in the treatment of chronic atrial fibrillation. Deslanoside inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations ^[1][2][3]. In Vitro: Deslanoside (Desacetyllanatoside C) is a metabolite of Lanatoside C^[4]. Deslanoside increases forearm blood flow and cardiac index and decreased heart rate concomitant with a marked decrease in skeletal muscle sympathetic nerve activity measured as an indicator of centrally mediated sympathetic nervous system activity^[1].