In acute decompensated heart failure treated with IV diuretics, which electrolyte abnormality is most common and requires monitoring?

• A. Hyperkalemia
• B. Hyponatremia
• C. Hypernatremia
• D. Hypokalemia

Answer: (D)

Potassium tends to drop with IV diuretic therapy, especially loop diuretics used in acute decompensated heart failure. These drugs increase potassium excretion in the distal nephron, so hypokalemia is the most common electrolyte disturbance you’ll monitor for. Low potassium can provoke dangerous arrhythmias and worsen other cardiac therapies, so frequent monitoring of serum potassium and timely correction are essential.

Hyponatremia is common in heart failure but is driven by neurohormonal factors and fluid balance more than the direct diuretic effect; hyperkalemia and hypernatremia are less typical in this setting with loop diuretics, making hypokalemia the most consistently encountered and clinically important abnormality to watch.