Pharmacology Mechanism of action of digitalis in atrial fibrillation is: A By decreasing cardiac contractility B Na+ K+ ATPase inhibition C Increase in refractoriness of AV nodal tissue D By causing bradycardia 💡 Explanation Mechanism of action of digitalis in atrial fibrillation is: ✓ Correct Answer: C. Increase in refractoriness of AV nodal tissue