Mechanism of digitalis in atrial fibrillation:
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
Decrease in contractility
Na+ K+ ATP ase pump inhibition
Increase refractoriness of AV node
Bradycardia
C.V.S