High-Grade Atrioventricular Block Reveals Rare Transthyretin Cardiac Amyloidosis With Unique Hemodynamics

TL;DR

A rare case of heart block revealed a rare condition called transthyretin cardiac amyloidosis with unusual blood pressure changes.

Contribution

Highlights a rare case linking high-grade AV block to undiagnosed ATTR amyloidosis with unique hemodynamics.

Findings

High-grade AV block was linked to undiagnosed transthyretin cardiac amyloidosis.

Patient exhibited severe supine hypertension and orthostatic hypotension.

Treatment with Tafamidis was initiated after pacemaker placement.

Abstract

Atrioventricular (AV) block is a common cardiac conduction disorder that is frequently encountered in clinical practice; however, the association with rare systemic conditions such as transthyretin amyloidosis (ATTR) is heavily underdiagnosed. ATTR amyloidosis is a systemic disorder characterized by the deposition of abnormal transthyretin protein fibrosis in various organs including the heart and vasculature, resulting in progressive organ dysfunction. We present a rare case of high-grade AV block unveiling ATTR cardiac amyloidosis with unusual hemodynamics, specifically severe supine hypertension with severe orthostatic hypotension. These findings posed a diagnostic challenge, underscoring the importance of a comprehensive diagnostic approach and meticulous review of medical history. Following pacemaker placement and the diagnosis of ATTR cardiac amyloidosis, our patient was started on a Tafamidis regimen.

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