Carcinoid Syndrome-induced Multi-valvular Heart Disease: A Rare Cause of Heart Failure in a 45-Year-Old Woman

Background: Carcinoid syndrome, a rare neuroendocrine disorder, can lead to progressive valvular fibrosis due to the excessive secretion of serotonin and other vasoactive substances. This typically affects the right-sided cardiac valves and rarely the left side. The resulting carcinoid heart disease represents an uncommon but serious cause of heart failure. Presentation of Case: We report the case of a 45-year-old woman admitted for progressive heart failure symptoms, including dyspnea, peripheral edema, and fatigue. She also experienced flushing and diarrhea suggestive of carcinoid syndrome. Transthoracic echocardiography revealed severe tricuspid, mitral, and aortic valve involvement, with biatrial dilation and features of severe stenosis and regurgitation. Work-up revealed elevated urinary 5-HIAA and chromogranin A levels, and imaging identified a hyper vascular ileocecal mass consistent with a neuroendocrine tumor. The diagnosis of carcinoid syndrome with multivalvular carcinoid heart disease was established. Discussion: This case illustrates the diagnostic challenge of distinguishing carcinoid heart disease from other etiologies such as rheumatic heart disease. The rare left-sided valvular involvement, likely due to high circulating serotonin levels, underscores the severity of tumor burden. Early identification through echocardiography and biochemical markers is crucial. Management requires both symptomatic treatment of heart failure and control of the underlying tumor through somatostatin analogs and surgical or oncologic intervention. Conclusion: Carcinoid-induced multivalvular heart disease is a rare but critical diagnosis in patients with neuroendocrine tumors. Optimal care requires a multidisciplinary approach combining cardiology, oncology, and cardiac surgery to improve outcomes and manage complex systemic involvement.