Which medication, among the following, is used in heart failure to increase cardiac contractility?

Which medication, among the following, is used in heart failure to increase cardiac contractility?

• A. Diuretics
• B. ACE inhibitors
• C. Vasodilators (hydralazine & nitrates)
• D. Digitalis to increase cardiac contractility

Answer: (D)

In heart failure, boosting the heart’s pumping strength requires a drug with a direct positive inotropic effect. Digitalis does this by inhibiting the Na+/K+ ATPase pump on cardiac myocytes. When this pump is blocked, intracellular sodium increases, which reduces the activity of the Na+/Ca2+ exchanger. As a result, intracellular calcium accumulates more during systole, allowing the heart muscle to contract more forcefully. The other options improve heart failure in different ways—by reducing fluid preload, lowering afterload, or slowing heart rate—but they do not directly increase the force of contraction. Digitalis uniquely provides an inotropic boost, though it carries a narrow therapeutic window and requires careful monitoring.

In heart failure, boosting the heart’s pumping strength requires a drug with a direct positive inotropic effect. Digitalis does this by inhibiting the Na+/K+ ATPase pump on cardiac myocytes. When this pump is blocked, intracellular sodium increases, which reduces the activity of the Na+/Ca2+ exchanger. As a result, intracellular calcium accumulates more during systole, allowing the heart muscle to contract more forcefully.

The other options improve heart failure in different ways—by reducing fluid preload, lowering afterload, or slowing heart rate—but they do not directly increase the force of contraction. Digitalis uniquely provides an inotropic boost, though it carries a narrow therapeutic window and requires careful monitoring.