Chapter 8. Antiarrhythmic and Antianginal Agents

Publisher Summary This chapter describes the various aspects of antiarrhythmic and antianginal agents. Cardiac arrhythmias generally result from enhanced automaticity or disturbances in conduction. These disturbances cause alterations in cardiac rate, regularity, origin of cardiac impulse, or sequence of activation of the atria and ventricles. A series of N -substituted-2-amino-l-(thienyl)ethanols were evaluated as β-blockers and was found to be less potent than propranolol as inhibitors of the tachycardic response to isoproterenol. A series of heterocyclic propanolamines had β-blocking activity, the most potent having ten times the activity of propranolol on the guinea pig atrial strip. UM-272, the dimethyl derivative of propranolol, exhibits neither the 6-blocking properties nor the local anesthetic properties of propranolol. UM-272 is effective against digitalis and myocardial infarction arrhythmias in the dog. In addition, UM-272 was shown to significantly increase ventricular fibrillation threshold and reduce the occurrence of ventricular fibrillation following acute occlusion of the left anterior descending coronary artery and its subsequent de-occlusion. Aprindine is a long-acting, orally effective antiarrhythmic agent that compares favorably with intravenous lidocaine in preventing ventricular arrhythmias after acute myocardial infarction.