Case Report
Light-chain deposition in myocardium usually manifests as amyloidotic restrictive cardiomyopathy. In rare cases paraproteinemia can deposite as a non-fibrillary infiltrate that does not show typical tintorial attributes of amyloidosis but resembles its clinical features. Clinical suspiction and correct diagnosis are important since early treatment of underlying cell plasma dyscrasia can reverse cardiac dysfunction. We present images from the case of a 47-year-old woman with fatal non-amyloidotic light-chain deposition cardiomyopathy that developed left atrial mechanical dysfunction while in sinus rhythm complicated with systemic arterial embolization.
Patient history prior to current observation :
A 47-year-old woman sustained a 8-month history of heart failure. She had been managed in an outpatient clinic. At symptoms onset, she underwent transthoracic echocardiography that revealed "concentric hypertrophy and normal ventricular function". Initial diagnosis of non-obstructive hypertrophic cardiomyopathy was made, but small doses of propranolol first, and verapamil later resulted in significant worsening of symptoms. Diuretics and vasodilators were started, but heart failure symptoms progressed. She was then referred to our hospital outpatient clinic for evaluation.
Clinical findings on admission, evolution and outcome :
Outpatient work-up in our hospital:
· ECG (fig. 1): Sinus rhythm, nonspecific intraventricular conduction delay and repolarization alterations.
· Chest X-ray (fig. 2): Cardiomegalia, mild bilateral pleural effusion, pulmonary vascular congestion and interstitial oedema.
· Blood tests: Haemogram, coagulation, serum creatinine, thyroid hormones, ferritin and angiotensin-converting enzime were normal. Erytrhocyte sedimentation rate was high at 80 mm/h. Serum electrophoresis showed a monoclonal peak of lambda light-chains, while levels of IgG, IgA and IgM were slightly decreased (fig. 3).
· Urine analysis: Proteinuria (2.1 g/dL). Monoclonal lambda light-chain peak of 3.5 mg/dL (Bence-Jones Proteinuria).
· Transthoracic echocardiography: Concentric (relative wall thickness 0.99) increment of left ventricular mass (113 g/m2). Left ventricular ejection fraction 58%. (fig. 4; fig. 5; fig. 6). Note that fractional shortening (fig. 4 and fig. 5) is well preserved, but longitudinal shortening assessed in fig. 6 is reduced. Left atrial dimensions were normal. Valves had no significant dysfunction. Mild pericardial and left pleural effusions were found. Mitral inflow (fig. 7 showed short E wave deceleration time (120 ms) and a hardly visible atrial contribution. Pulmonary vein flow(fig. 8) showed a marked prevalence of the diastolic component and the absence of retrograde A wave. Both Doppler patterns were consistent with restrictive physiology and left atrial mechanical dysfunction. Pulsed tissue Doppler interrogation of mitral annulus at both its septal and lateral points disclosed E' wave velocity of 6 cm/s, pointing towards restrictive cardiomyopathy rather than constrictive pericarditis.
· Rectal mucose biopsy was negative for Congo red staining.