The effects of OPC-88117, a new investigational antiarrhythmic drug, on early and delayed afterdepolarizations (EAD and DAD, respectively) were assessed in vitro in canine Purkinje fibers and in vivo in the canine right ventricle. OPC-88117 had similar electrophysiologic properties to class I antiarrhythmic agents in that it decreased V̇max. OPC-88117 decreased the amplitude and prolonged the coupling interval of DAD induced by acetylstrophanthidin. Likewise, OPC-88117 suppressed EAD induced in vitro by 4-aminopyridine. In vivo, cesium-induced EAD, ventricular arrhythmia, and atrioventricular block were suppressed by OPC-88117. In summary, OPC-88117 suppressed DAD and EAD in vitro and inhibited EAD and triggered activity in the in situ canine heart.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine