Cardiac dysrhythmia is any abnormality in rate, regularity, site of origin of the cardiac impulses or a disturbance in conduction that cause abnormal activation sequences of the myocardium.Cardiac dysrhythmias could occur in up to 25% of patients treated with digitalis, 50% of anaesthetized patients and over 80% of patients of myocardial infarction.Coronary heart disease is often a trigger for cardiac dysrhythmia. There is an over activity of the late sodium entry (INaL) during ischemia in phase 3 of action potential with subsequent calcium overload through interference with sodium-calcium exchange. Increased intracellular calcium triggers cardiac dysrhythmia.Ranolazine is an anti-anginal drug that selectively inhibits late INa 10-fold more than peak INa. Blocking of late sodium channels during phase 3 of cardiac action potential leads to a decrease in late sodium entry with subsequent decrease in intracellular calcium, which will probably improve ischemia and may have antidysrhythmic potential.