Which sign is indicative of carcinoid syndrome in the context of right-sided heart failure?

In the context of carcinoid syndrome, tricuspid regurgitation is a key sign associated with right-sided heart failure. Carcinoid syndrome is typically caused by serotonin-secreting tumors, often located in the gastrointestinal tract, which can lead to fibrosis of the right heart valves. This fibrotic process primarily affects the tricuspid valve, leading to regurgitation.

Tricuspid regurgitation results when the tricuspid valve does not close properly during ventricular contraction, causing blood to flow backward into the right atrium. This can lead to symptoms of right-sided heart failure, as the heart struggles to effectively pump blood into the lungs for oxygenation. The mechanism of damage is largely due to the persistent high levels of circulating serotonin, which promotes fibrous tissue growth and results in valve abnormalities.

In contrast, the other conditions listed do not align with the typical pathophysiology of carcinoid syndrome. For example, mitral stenosis and aortic regurgitation predominantly involve the left side of the heart and are not directly related to the fibrotic changes caused by carcinoid syndrome. Pulmonic stenosis also generally has a different etiology and does not directly relate to the right heart changes observed in