Digoxin is used for treatment of congestive hea failure. It acts by inhibiting:-

Digoxin acts by inhibiting Na+K+ATPase of myocardial fibres by binding to its extracellular face- Accumulation of sodium in the cardiac cell- increased intracellular calcium. This Ca2+ is shifted to sarcoplasmic reticulum with the help of SERCA for storage. Thus, during systole, entry of calcium from membrane Ca2+ channels triggers release of high amount of Ca2+ from the sarcoplasmic reticulum and result in increased contractility.