Carcinoid Heart Disease: A Rare Complication of Metastatic Neuroendocrine Tumor.

Carcinoid heart disease (CHD), also known as Hedinger syndrome, is a rare but significant cardiac complication associated with metastatic neuroendocrine tumors (NETs). These tumors secret bioactive substances such as serotonin, leading to fibrotic changes primarily affecting the right-sided heart valves. A case study involving a 69-year-old male presented with a four-month history of diarrhea and a new systolic heart murmur.