Dilated Cardiomyopathy and Severe Functional Valvular Regurgitation in a Young Adult with Prior Childhood Chemotherapy: Progressive Ventricular Dysfunction Despite Surgical Correction and Optimal Medical Therapy

Background: Late cardiotoxicity is a recognized complication in survivors of childhood cancer treated with potentially cardiotoxic agents, particularly anthracyclines. These therapies may cause progressive myocardial injury through mechanisms involving oxidative stress, mitochondrial dysfunction, and cardiomyocyte apoptosis. Over time, this process can lead to ventricular remodeling, dilated cardiomyopathy, and heart failure. Advanced ventricular dilation frequently results in functional mitral and tricuspid regurgitation, further worsening hemodynamic burden and clinical outcomes. Case summary: We report the case of a 42-year-old man with a history of non-Hodgkin lymphoma diagnosed in childhood and treated with chemotherapy, without subsequent cardiologic follow-up. From the age of 29, he developed progressive heart failure symptoms. Transthoracic echocardiography revealed severe functional mitral regurgitation with mixed mechanism (Carpentier type I due to annular dilation and type IIIa due to leaflet restriction) and massive tricuspid regurgitation, associated with severe atrial dilation, grade III diastolic dysfunction, and pulmonary hypertension. Left ventricular systolic dysfunction was documented with an ejection fraction of 36% and markedly reduced global longitudinal strain (−11%), consistent with non-ischemic dilated cardiomyopathy. The patient underwent mitral valve replacement and tricuspid valve repair but developed intraoperative cardiac arrest and postoperative mixed shock. Persistent severe ventricular dysfunction (LVEF 26%, GLS −8%) and multiple complications were observed. Conclusion: This case highlights the importance of long-term cardiovascular surveillance in childhood cancer survivors and the role of strain imaging in detecting chemotherapy-related cardiomyopathy.