What is the effect on the heart when cardiac glycosides are administered?

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Cardiac glycosides,such as digoxin,have a positive inotropic effect on the heart;they increase the force of myocardial contractions.The greater force of contractions increases the cardiac output and reduces diastolic heart size.As end-diastolic pressures decrease,pulmonary and systemic venous pressures are reduced.The positive inotropic effect is produced by the inhibition of the Na⁺/K⁺ ATPase pump,leading to increased intracellular sodium and inhibition of the Na⁺/Ca²⁺ exchanger.Digoxin-induced inhibition of the Na⁺/Ca²⁺ exchanger leads to increased calcium,an electrolyte involved in the contraction of cardiac smooth muscle.

What Is the Effect on the Heart When Cardiac Glycosides