CASE — Multiple myeloma. Cardiac amyloidosis most characteristically produces which type of cardiomyopathy?

Correct answer: B. Restrictive cardiomyopathy

• A. Dilated cardiomyopathy is associated with other causes (e.g., alcohol, viral), not amyloid.
• B. Correct. Amyloid infiltration stiffens the myocardium, producing a RESTRICTIVE cardiomyopathy (impaired diastolic filling).
• C. The walls appear thickened on echo (a 'pseudohypertrophy'), but functionally it is restrictive, not true HOCM.
• D. Cardiac amyloid is a major cause of morbidity; the heart is very much involved.

Note: Amyloid deposition thickens the ventricular walls (a hypertrophic APPEARANCE) but the functional classification — and the standard exam answer — is restrictive cardiomyopathy.