Hemojuvelin-Associated Juvenile Hemochromatosis: Fulminant Heart Failure, Complete Heart Block, and Ventricular Arrhythmias

Background: Hemojuvelin (HJV)-associated juvenile hemochromatosis is an uncommon subtype of hereditary hemochromatosis that often presents before age 30, with significant cardiac complications. Case Summary: A 28-year-old woman with hypogonadotropic hypogonadism presented with cardiac arrest. Subsequent evaluation revealed biventricular dysfunction, ventricular fibrillation, and complete heart block. Endomyocardial biopsy demonstrated extensive iron deposition, with subsequent genetic confirmation of HJV mutations. Discussion: HJV mutation results in a profound elevation of serum iron that preferentially deposits in cardiac tissue owing to high expression of L-type calcium channels. The underlying pathophysiology enables unregulated entry of iron into myocardium, resulting in accelerated development of cardiomyopathy and associated conduction abnormalities. Take-Home Message: HJV-associated juvenile hemochromatosis should be considered in younger adults presenting with idiopathic cardiomyopathy, ventricular arrhythmias, or complete heart block, as timely diagnosis and treatment are essential to prevent devastating cardiovascular outcomes.