Cardiac glycoside

Any drug used in the treatment of congestive cardiac failure (CCF) or cardiac arrhythmia, by inhibiting the Na⁺ / Ka ⁺ / ATP-ase pump. This inhibition increases the amount of Ca⁺⁺ ions available for contraction and improves cardiac output and reduces distention of the heart.

It has an antiarrhythmic effect by prolonging the refractory period of the AV node (Atrio-ventricular), reducing the number of impulses reaching the ventricles. Cardiac output is restored but atrial fibrillation or atrial flutter are not abolished.