Nonamyloidotic light chain deposition cardiomyopathy.

Abstract

A 56-year-old woman with a newly diagnosed monoclonal plasma cell dyscrasia and kappa light-chain cast nephropathy was referred for exclusion of cardiac involvement prior to autologous stem-cell transplantation. Patient history revealed mild exertional dyspnoea with elevated natriuretic peptides (NT-proBNP 2010 ng/mL) and mildly elevated high-sensitivity cardiac troponin T (26 ng/L). Her electrocardiogram was not specific for cardiac amyloidosis and without conduction abnormalities. In spite of normal chamber dimensions, normal systolic function and absence of restrictive cardiomyopathy in transthoracic echocardiography (Supplementary data online) and cardiovascular magnetic resonance (CMR) scan (Panel A), CMR revealed a highly elevated myocardial extracellular volume (ECV) of ≥45% (Panel B) and presence of mild bilateral pleural as well as pericardial effusion (Panel A). There was no evidence of myocardial oedema, focal fibrosis, or myocardial infarction. 99mTc-DPD scintigraphy excluded transthyretin-related (ATTR) cardiac amyloidosis (Perugini Score = 0). Cardiac biopsy did...