Endomyocardial biopsy-proven light chain amyloidosis (AL) without echocardiographic features of infiltrative cardiomyopathy

In conclusion, we report 5 patients with endomyocardial biopsy demonstration of extensive cardiac AL without the classic findings of infiltrative cardiomyopathy. This subset lacking overt thickening represents one part of the spectrum of cardiac AL. All 5 patients had immunoglobulin light chain amyloid, with the demonstration of either a monoclonal protein in the serum or urine or detection of immunoglobulin light chains within the amyloid deposits themselves.