What is a primary cause of right-sided heart failure?

The primary cause of right-sided heart failure is blood backing up in systemic circulation. In right-sided heart failure, the heart struggles to pump blood effectively to the lungs for oxygenation. As a result, blood accumulates in the body's systemic circulation, leading to symptoms such as swelling in the legs and abdomen, as well as elevated pressure in the veins. This congestion in systemic circulation occurs because the right ventricle is unable to handle the volume of blood returning from the body, causing fluid to leak into tissues.

The other options, while possibly related to heart failure, do not specifically identify the primary mechanism behind right-sided heart failure. Pulmonary congestion typically relates to left-sided heart failure, fluid retention in the lungs is a symptom of compromised left ventricular function, and coronary artery disease can affect the heart but is not directly a primary cause of right-sided heart failure.