Which of the following is a common symptom indicating severe right-sided heart failure?

Severe right-sided heart failure is often indicated by Kussmaul's sign, which is characterized by the paradoxical rise in jugular venous pressure during inspiration. In healthy individuals, when inhaling, venous return to the heart increases, leading to a decrease in jugular venous pressure. However, in cases of right-sided heart failure, the right ventricle is unable to accommodate the increased venous return, causing the jugular venous pressure to rise instead. This sign is particularly associated with conditions such as constrictive pericarditis and restrictive cardiomyopathy, which can lead to impaired filling of the right heart.

Other symptoms listed, while relevant to heart failure in general, do not specifically indicate severe right-sided heart failure. Fluid overload can be a symptom of heart failure but is not exclusive to right-sided failure. Orthopnea is typically associated with left-sided heart failure due to pulmonary congestion, making it less characteristic of right-sided issues. Pulmonary congestion is more indicative of left-sided heart failure as well, where fluid backs up into the lungs. Therefore, Kussmaul's sign distinctly reflects the unique pathophysiology of severe right-sided heart failure.