Aprindine: A class Ib anti-arrhythmia agent used to manage ventricular and supraventricular arrhythmias.Bepridil: A long-acting calcium-blocking agent with significant anti-anginal activity. The drug produces significant coronary vasodilation and modest peripheral effects. It has antihypertensive and selective anti-arrhythmia activities and acts as a calmodulin antagonist.Indenes: A family of fused-ring hydrocarbons isolated from coal tar that act as intermediates in various chemical reactions and are used in the production of coumarone-indene resins.Anti-Arrhythmia Agents: Agents used for the treatment or prevention of cardiac arrhythmias. They may affect the polarization-repolarization phase of the action potential, its excitability or refractoriness, or impulse conduction or membrane responsiveness within cardiac fibers. Anti-arrhythmia agents are often classed into four main groups according to their mechanism of action: sodium channel blockade, beta-adrenergic blockade, repolarization prolongation, or calcium channel blockade.Biperiden: A muscarinic antagonist that has effects in both the central and peripheral nervous systems. It has been used in the treatment of arteriosclerotic, idiopathic, and postencephalitic parkinsonism. It has also been used to alleviate extrapyramidal symptoms induced by phenothiazine derivatives and reserpine.