Endomyocardial biopsy samples are taken from which heart chamber?

• A. Right ventricle
• B. Left ventricle
• C. Right atrium
• D. Left atrium

Answer: (A)

Endomyocardial biopsy is typically done through a venous route to obtain tissue from the endocardium of the right ventricle. The right ventricle is readily accessible via the internal jugular or femoral vein, and a bioptome can safely sample the endocardial surface (often the septal/apical area). This provides representative myocardial tissue for diagnosing conditions such as myocarditis, cardiomyopathy, and transplant rejection. Sampling the left ventricle would require arterial access and carries higher risks (perforation, embolism, bleeding), making it less favored as the routine site. Right atrial or left atrial sampling is not the standard approach for endomyocardial biopsy because it yields less diagnostic tissue for these myocardial conditions.