Table 2.
| Diagnostic modality | Sensitivity, specificity (Percentages) | Findings consistent with cardiac amyloid |
|---|---|---|
| EKG | 90%, 90% | Diffuse low voltage QRS (<5 mm height), QRS deviation, LBBBs, pseudo–infarction |
| Echocardiography with strain imaging | 90–95%, 80-85% | Biventricular hypertrophy, inter-ventricular septal hypertrophy, bi-atrial dilation, decreased longitudinal strain in mid and basal wall with relative sparing of apical function |
| Cardiac MRI | 80%, 94% | Global transmural or subendocardial late gadolinium enhancement, expansion of ECV leading to enhanced T1 mapping |
| Nuclear Scintigraphy (Positron Emission Tomography – PET, Technetium labelled imaging) | 95%, 98% | Characteristic enhancement due to binding of radiotracer to amyloid |
| Histopathology | 100% sensitivity for endomyocardial biopsy, Tissue biopsy has sensitivity of 75% and specificity of 92% |
Fat pad biopsy, Endomyocardial biopsy with immunohistochemical staining showing extracellular deposits of AL amyloid with Congo red stain showing apple-green birefringence under polarized microscopy |
MRI: Magnetic resonance imaging, LBBB: Left bundle branch block, ECV: Extracellular volume, PET: Positron emission tomography