<prompt> All are true statement about digitalis action EXCEPT:Increases cardiac contractionPumps sodium out of cellIncreases intracellular calciumCauses bradycardia  <response>: Ans. b Pumps sodium out of cell Digitalis is one of the cardiac glycosides which increases myocardial contractility and output in a hypodynamic heart without a proportionate increase in oxygen consumption. Compounds in cardiac glycosides group include: digoxin, digitoxin, strophanthin, ouabain etc. MOA of Digitalis: binds to NaKATPase of myocardial fibres and inhibits this enzyme. This leads to progressive accumulation of Na intracellularly which indirectly results in intracellular Calcium accumulation. ACTION: Digitalis increases the force of contraction and decreases the heart rate It also decreases the AV conduction, hence contraindication in WPW syndrome. Causes diuresis in CHF patients Causes decrease in peripheral resistance in CHF patients because of withdrawal of reflex sympathetic overactivity 