Anesthesia Knowledge Test 24 (AKT-24) Practice 2026 - Free Anesthesia Practice Questions and Study Guide

The mechanism of action of Digoxin involves the blocking of the sodium/potassium ATPase pump in cardiac myocytes. This inhibition leads to an increase in intracellular sodium concentration. As a result, the sodium-calcium exchanger (which usually extrudes one calcium ion from the cell in exchange for three sodium ions) works less effectively, causing calcium to accumulate within the cells. The increased availability of calcium enhances myocardial contractility, which is particularly beneficial in the treatment of conditions such as heart failure and certain types of arrhythmias.

The action of Digoxin not only boosts cardiac contractility but also has implications for heart rate and rhythm, as it can slow conduction through the atrioventricular (AV) node and help manage atrial fibrillation. The other choices presented do not accurately describe the primary action of Digoxin.