The heart of the matter

We agree that endomyocardial biopsy remains the ideal test to confirm cardiac amyloidosis, especially in cases of isolated cardiac amyloidosis. However, in cases of systemic amyloidosis with suspected cardiac involvement, the need for endomyocardial biopsy can be obviated by the combined findings of low-voltage QRS complexes on electrocardiography, a typical restrictive pattern on transmitral Doppler blood flow imaging and the classic “granular sparkling” appearance of the myocardium with 2-dimensional echocardiography.1 These findings, together with the results of biopsy of subcutaneous fat, the rectum or gums, or the bone marrow (all of which are safer and less difficult and require less expertise than endomyocardial biopsy), allow cardiac amyloidosis to be diagnosed with great certainty. Radionuclide scintigraphic scanning with iodine 123-labelled serum amyloid P, which localizes signals to organs with amyloid deposits, is another noninvasive test that can be used in certain patients.

Endomyocardial biopsy is limited in its ability to identify any cardiac abnormality that is not diffuse, insofar as only a few biopsy samples are typically obtained and evaluated. The question is whether this method is warranted when an accurate diagnosis can be made on the basis of results of noninvasive testing. We suggest that endomyocardial biopsy be used as a confirmatory test rather than as a screening method.

Sandeep Arora Anju Arora Ravinder P.S. Makkar Amitabh Monga Department of Medicine Sitraram Bhartia Institute of Science and Research New Delhi, India