Case report: multiple myeloma presenting as a diastolic heart failure with no evidence of amyloidosis.

The development of severe right sided congestive heart failure led to a diagnosis of immunoglobulin G (lambda) myeloma with a predominance of light chains. Cardiac catheterization and endomyocardial biopsy showed a severe diastolic dysfunction of both right and left ventricles and extensive myocardial infiltration by intercellular fibrillar tissue, which was not amyloid. This is a rare presentation of immunoglobulin deposition disease associated with immunocytic dyscrasias.