Mechanism of digitalis in atrial fibrillation:
Decrease in contractility
Na+ K+ ATP ase pump inhibition
Increase refractoriness of AV node
Bradycardia
Ans. C. Increase refractoriness of AV nodeDigoxin is inotropic agent used in heart failure. It has positive inotropic effect and negative chronotropic effect. Inotropic effect is due to blockade of Na+K+ATPase pump. Chronotropic effect is due to vagomimetic effect which increase the refractoriness of AV node. This mechanism is utilized in atrial flutter and fibrillation. Answer is C
C.V.S