Parasympathetic denervation of the heart: an early sign of symptomatic TTR-FAP

Abstract

Autonomic nerves may become involved in Transthyretin Familial Amyloid Polyneuropathy (TTR-FAP), and autonomic dysfunction is considered a red flag for TTR-FAP Although autonomic symptoms are easy to recognize for clinicians, they may be subtle or inconstant at early stages, limiting its diagnostic value. Abnormalities in heart rate variability (HRV), an index of parasympathetic cardiac innervation, has been shown to be present in most TTR-FAP patients. However, at what time during the course of the illness these abnormalities appear has not been ascertained. To elucidate this, we analysed the frequency of HRV abnormalities in carriers of TTR gene mutations at the time they transitioned from asymptomatic to symptomatic TTR-FAP.