Carpal tunnel syndrome as an early red-flag sign of ATTRwt amyloidosis

Excerpt

A 62-year-old male patient with bilateral carpal tunnel syndrome (CTS) underwent surgical carpal tunnel release procedures of the wrists under local anesthesia. A small amount of transthyretin amyloid (ATTR) deposition was revealed in the tenosynovial tissue (Figure 1A, B). A chest X-ray did not show either cardiomegaly or pulmonary congestion (Figure 1C). Sinus rhythm with a slightly prolonged PQ interval of 220 msec, but not low voltage in the limb leads or pseudo-infarct pattern in the right precordial leads was observed on electrocardiography (Figure 1D). A transthoracic echocardiogram indicated diffuse left ventricular (LV) hypertrophy (12mm) with preserved LV systolic performance (LV ejection fraction=66%) and diastolic function (E/e’=6.2). The patient was referred to our hospital for further investigation of cardiac amyloidosis. Plasma N-terminal pro-brain natriuretic peptide level was measured at 76.4 pg/mL. Cardiac magnetic resonance imaging showed no myocardial late gadolinium enhancement. ^99mTc-labeled bone scintigraphy indicated slightly cardiac uptake on planar imaging (Figure 1E). Single-photon emission computed tomography/computed tomography fusion imaging confirmed the uptake to myocardium (Figure 1F). ATTR deposition was also found in the endomyocardial biopsy specimen (Figure 1G,H). Gene mutation analysis determined the patient had a wild-type transthyretin (ATTRwt) amyloidosis.

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