Endomyocardial biopsy can be indicated for which cardiomyopathy?

• A. Restrictive cardiomyopathy
• B. Dilated cardiomyopathy
• C. Hypertrophic cardiomyopathy
• D. Arrhythmogenic right ventricular cardiomyopathy

Answer: (A)

Endomyocardial biopsy is most helpful when the cardiomyopathy is suspected to be driven by an infiltrative or inflammatory process affecting the myocardium. In restrictive cardiomyopathy, deposits or infiltration (such as amyloidosis, sarcoidosis, or iron overload) can be confirmed with tissue sampling, which not only establishes the diagnosis but also guides disease-specific therapy. The other cardiomyopathies are typically diagnosed and managed with imaging and genetics, and biopsy is unlikely to change management and carries sampling risk. Arrhythmogenic right ventricular cardiomyopathy is diagnosed primarily from imaging, ECG, and family history, with biopsy playing a limited or discordant role. Therefore, restrictive cardiomyopathy is the best fit for a biopsy-indicated scenario.