Which of the following is a sign of left heart failure?

In left heart failure, the primary issue is the inability of the left ventricle to effectively pump blood to meet the body's needs. This inefficiency leads to a backup of blood in the pulmonary circulation, resulting in a variety of symptoms. Dyspnea, or difficulty breathing, is a hallmark symptom of left heart failure and can occur at rest as the condition worsens. It is often related to pulmonary congestion due to fluid accumulation in the lungs, prompting a sense of breathlessness during both exertion and rest.

While other options may be associated with cardiac issues, they are not specific to left heart failure. For instance, jugular venous distention (JVD) typically indicates right heart failure or fluid overload, dependent edema is more common in right-sided heart failure as it influences fluid distribution leading to lower extremity swelling, and hepatomegaly is associated with right heart failure due to congestion in systemic circulation. Each of these conditions reflects issues with different aspects of heart function, which helps differentiate between right and left heart failure. Therefore, the presence of dyspnea at rest is a strong indicator of left heart failure, making it the most accurate choice among the options.