Severe Right Ventricular Dilation Due to Selenium Deficiency in a Patient After Gastric Bypass

Selenium deficiency is a rare but reversible cause of cardiomyopathy increasingly recognized as a late nutritional complication of bariatric surgery, yet it is not consistently included in routine postoperative surveillance.This report describes a 40-year-old woman who presented three years after Roux-en-Y gastric bypass (RYGB) with progressive dyspnea, weakness, lower extremity edema, and dizziness in the setting of nonadherence to postoperative nutritional supplementation.She was hypotensive and bradycardic with jugular venous distension, elevated B-type natriuretic peptide (BNP), and chest imaging showing cardiomegaly with a right-sided pleural effusion.Echocardiography revealed severe, isolated right ventricular and atrial dilation with reduced right-sided systolic function, and further evaluation identified a markedly low serum selenium level (25 µg/L) with normal thyroid function and other trace elements.She was treated with intravenous selenium repletion (150 µg/day) alongside inotropic and diuretic support, with rapid hemodynamic improvement and complete resolution of right ventricular and atrial dilation on repeat echocardiography within one week.This case illustrates that selenium-deficiency cardiomyopathy can present with isolated right ventricular involvement, distinct from the left-ventricular predominance classically described, and underscores the importance of considering trace element deficiency in unexplained cardiomyopathy with a remote history of bariatric surgery.Prompt recognition and repletion can produce dramatic, complete reversal of cardiac dysfunction.