Pulmonary edema is most directly a result of which heart condition?

• A. Left-sided heart failure
• B. Right-sided heart failure
• C. Cor pulmonale
• D. Pulmonary embolism

Answer: (A)

Pulmonary edema occurs most directly when the left side of the heart fails to move blood forward. That failure causes blood to back up into the left atrium and pulmonary veins, raising the pressure in the pulmonary capillaries. The elevated hydrostatic pressure drives fluid out of the capillaries into the lung interstitium and alveoli, leading to edema and impaired gas exchange. This direct process comes from left-sided heart failure, making it the best answer.

Right-sided heart failure tends to cause systemic venous congestion (legs, abdomen), cor pulmonale is right heart failure due to lung disease, and a pulmonary embolism is a blockage in the pulmonary vessels that can cause hypoxia and stress but does not directly produce the pulmonary edema through elevated left-sided pressures.