All are true statement about digitalis action EXCEPT:
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 Na+K+ATPase 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)
Digitalis
Increases cardiac contraction
Pumps sodium out of cell
Increases intracellular calcium
Causes bradycardia
Pumps sodium out of cell