New Drug Discovery of Cardiac Anti-Arrhythmic Drugs: Insights in Animal Models

In the normal heart cardiac rhythm is controlled by microscopic and macroscopic structures. Abnormality of pacemaker or electrical conduction aberrations causes arrhythmic disorders. Cardiac Arrhythmias may be fortunate, typical, threatening and eventually fatal. Cardio-vascular arrhythmia happens commonly in clinical practise affecting drastically to the patients on digitalis, anaesthesia and acute myocardial infarction. Both traditional and genetic animal models of arrhythmias, their characteristics, and their significance are summarized as: In Vitro Models: Isolated guinea pig papillary muscles, Action potential and refractory period in isolated guinea pig papillary muscle, Langendorff technique & Acetylcholine or potassium induced arrhythmia. In Vivo Models- Chemically induced arrhythmia: Aconitine antagonism in rats, Digoxin induced arrhythmia in rats, Strophanthin/ouabain induced arrhythmia, Adrenaline induced arrhythmia & Calcium induced arrhythmia. Electrically induced arrhythmia: Ventricular fibrillation electrical threshold, Programmed electrical stimulation induced arrhythmia & Sudden coronary death models in dogs. Exercise induced ventricular fibrillation. Mechanically induced arrhythmia: Reperfusion arrhythmia in rats, Reperfusion arrhythmia in dogs & Two stage coronary ligation in dogs. Genetic models of arrhythmias. Conclusion: Experimental models of cardiac arrhythmias, traditional and genetic gives quick summary of the most popular animal models, their characteristics, and their significance for new drug discovery of antiarrhythmic agents.