<p>Digoxin is a cardiac glycoside used in the management of particularly atrial fibrillation and in heart failure.The principal actions of digoxin are an increase in the force of myocardial contraction (positive inotropic activity and a reduction in the conductivity of the heart particularly in conduction through the atrioventricular node. Digoxin also has a direct action on vascular smooth muscle and indirect effects mediated primarily by the autonomic nervous system and particularly by an increase in vagal activity.</p>