Septal thickness to QRS voltage ratio in Lead I/aVR: A simple tool for estimating cardiac amyloid burden

Abstract

Background

Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy associated with adverse outcomes. Quantification of myocardial amyloid burden is essential for risk stratification. Although cardiac magnetic resonance (CMR)-derived extracellular volume (ECV) is the reference standard for non-invasive assessment, its use is limited by cost and availability. Therefore, simple and widely accessible tools to estimate amyloid burden are needed. This study aimed to evaluate whether a novel integrated echocardiographic–electrocardiographic (echo–ECG) index, based on the ratio of maximum septal thickness (MST) to QRS voltage in lead I and/or aVR, correlates with CMR-derived ECV in patients with CA.