Unmasking AL Cardiac Amyloidosis During Familial Cardiomyopathy Screening

Figures

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  Figure 1. Initial Diagnostic Workup (A) 12-lead electrocardiogram showing sinus rhythm at 88 beats/min, normal axis, and anteroseptal QS pattern. No atrioventricular block or low-voltage QRS complexes are noted. (B) Bone scintigraphy demonstrated no myocardial tracer uptake, consistent with Perugini grade 0. (C and D) Transthoracic echocardiography in the parasternal long-axis view (C) and apical 4-chamber view (D) showing severe hypertrophy. (E) Strain imaging demonstrated a pathologic global longitudinal strain of −17% (normal range −18% to −22%).

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  Figure 2. Cardiac Magnetic Resonance (A) Severe concentric left ventricular hypertrophy (blue arrow) with a maximum wall thickness of 17 mm. (B) shows Late gadolinium enhancement (LGE) in the interventricular septum and both atria (orange arrows). (C and D) Native T1 mapping (1,208 ms ± 29.5), postcontrast T1 (507 ms), and extracellular volume 22% with a hematocrit of 43.1%, all within normal ranges. 4C = 4 chambers.

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  Figure 3. Endomyocardial Biopsy Histopathologic specimens stained with hematoxylin and eosin, with orange arrows indicating amorphous reticular deposits (A) and involvement of small-caliber vessels (B). Congo red staining, with blue arrows highlighting red-orange staining of amorphous deposits within the interstitium (C) and vessel walls (D). Specimen under polarized light, with white arrow indicating apple-green birefringence (E). Immunohistochemical staining was negative for transthyretin (TTR) (F) and κ light chains (G) and positive for λ light chains (H).