Which of the following is an indication for endomyocardial biopsy?

• A. New onset unexplained heart failure
• B. Routine chest X-ray
• C. Hearing loss
• D. Deep vein thrombosis

Answer: (A)

Endomyocardial biopsy is used when you need a tissue diagnosis to define the cause of cardiomyopathy or unexplained heart failure and that diagnosis would change management. The most fitting indication is new onset unexplained heart failure, because obtaining a tissue sample can reveal myocarditis, infiltrative diseases, or other etiologies that would steer specific therapies (such as immunosuppression for inflammatory conditions or antiviral therapy for certain viral myocarditides, and in transplant patients, to assess rejection). Routine chest X-ray is a noninvasive imaging study and does not require biopsy. Hearing loss and deep vein thrombosis do not involve myocardial tissue pathology and are not indications for sampling the endomyocardium.