TTR and carpal tunnel syndrome: Vianello et al. in a study population of 53 male patients with bilateral CTS (median age 73 years) found unexplained left ventricular hypertrophy in 6 (11%) individuals, 4 of whom underwent bone scan (two patients resulted positive for heart retention of bone tracer both classified as grade 2 on the Perugini scale) and negative for TTR gene mutations leading to the diagnosis of wild-type ATTR-CA.