MS‐551: Pharmacological profile of a novel class III antiarrhythmic agent

Isolated canine Purkinje fibers and anesthetized open-chested dogs

MS-551 (0.1-10 μg/ml in vitro; 0.1-30 mg/kg i.v. in vivo; continuous infusion 2 mg/kg/min for 50 min)

d-sotalol (0.1-10 mg/kg i.v.) for hemodynamic comparison

Electrophysiological properties (action potential duration, atrial and ventricular effective refractory periods, intracardiac conduction time) and hemodynamics (heart rate, LVdP/dtmax)surrogate