Introduction: Light chain deposition disease (LCDD) can involve the heart
and cause severe heart failure. Cardiac involvement is usually described in
the advanced stages of the disease. We report the case of a woman in whom
restrictive cardiomyopathy due to LCDD presented with paroxysmal atrial
fibrillation. Case presentation: A 55-year-old woman was admitted to our
emergency department because of palpitations. In a recent blood test, serum
creatinine was 1.4 mg/dl. She was found to have high blood pressure, left
ventricular hypertrophy and paroxysmal atrial fibrillation. An
ACE-inhibitor was prescribed but her renal function rapidly worsened and
she was admitted to our nephrology unit. On admission serum creatinine was
9.4 mg/dl, potassium 6.8 mmol/l, haemoglobin 7.7 g/dl, N-terminal pro-brain
natriuretic peptide 29894 pg/ml. A central venous catheter was inserted and
haemodialysis was started. She underwent a renal biopsy which showed kappa
LCDD. Bone marrow aspiration and bone biopsy demonstrated kappa light chain
multiple myeloma. Echocardiographic findings were consistent with
restrictive cardiomyopathy. Thalidomide and dexamethasone were prescribed,
and a peritoneal catheter was inserted. Peritoneal dialysis has now been
performed for 15 months without complications. Discussion: Despite the
predominant tubular deposition of kappa light chain, in our patient the
first clinical manifestation of LCDD was cardiac disease manifesting as
atrial fibrillation and the correct diagnosis was delayed. The clinical
management initially addressed the cardiovascular symptoms without paying
sufficient attention to the pre-existing slight increase in our patient's
serum creatinine. However cardiac involvement is a quite uncommon
presentation of LCDD, and this unusual case suggests that the onset of
acute arrhythmias associated with restrictive cardiomyopathy and impaired
renal function might be related to LCDD