Tecadenoson (CVT-510) is a selective A1 adenosine receptor agonist. IC50 & Target: Target: A1 adenosine receptor^[1] In Vitro: In the atrial-paced isolated heart, Tecadenoson is approximately 5 fold more potent to prolong the stimulus-to-His bundle (S-H interval), a measure of slowing AV nodal conduction (EC₅₀=41 nM) than to increase coronary conductance (EC₅₀=200 nM). At concentrations of Tecadenoson (40 nM) and diltiazem (1 μM) that causes equal prolongation of S-H interval (∼10 ms), diltiazem, but not Tecadenoson, significantly reduces left ventricular developed pressure (LVP) and markedly increases coronary conductance. Tecadenoson shortens atrial (EC₅₀=73 nM) but not the ventricular monophasic action potentials (MAP)^[1]. In Vivo: In atrial-paced anaesthetized guinea-pigs, intravenous infusions of Tecadenoson and diltiazem causes nearly equal prolongations of P-R interval^[1]. Tecadenoson (2, 5, 20 μg/kg i.p.) causes a rapid and sustained dose-dependent decrease in NEFA at doses that do not cause bradycardia. Tecadenoson given at 50 μg/kg causes a significant bradycardia (50% decrease in heart rate at 25 min^[2].