A Straining Heart: Transthyretin Amyloidosis as a Cause of Heart Failure.

Cardiac amyloidosis is a disease caused by the deposition of amyloid fibrils in the extracellular space of the heart, most often by immunoglobulin light chains or by transthyretin. It is often underdiagnosed because the signs and symptoms are nonspecific or due to the false perception that the diagnosis always requires an endomyocardial biopsy. Transthyretin amyloidosis is being increasingly recognized as a cause of heart failure, particularly in patients with heart failure with preserved ejection fraction (HFpEF).