Multivendor Analysis of Left Atrial Strain using Multilayer Analysis

Abstract

Background: Left atrial strain (LAS) is increasingly being recognised as a measure of left atrial function. Different vendors have proposed different methods of measuring LAS in echocardiography. Aims: To determine if there is a difference between multilayer endocardial and mid-myocardial measurements of LA strain on General Electric (GE) Echopac compared to TOMTEC endocardial strain. Methods: Peak reservoir left atrial strain (LAS) was measured on 20 healthy controls using two different software packages. GE Echopac (v201) 2D-speckle tracking echocardiography technique (LV package) was used to measure conventional mid-myocardial (GE-mid) and endocardial (GE-endo) LAS. This was compared to LAS measurement using TOMTEC (v4.6) which uses an endocardial tracking technique. LAS was measured in 4ch and 2ch views and average biplane strain measurement was obtained. Results: The mean of GE-mid LAS was 39 ± 5.8%, GE-endo LAS was 48.0 ± 7.8%, and TOMTEC LAS was 44.9 ± 6%. GE-mid and GE-endo LAS correlated well with TOMTEC LAS (r = 0.9, p < 0.001 for both). On Bland-Altman Analysis, GE-mid LAS measurements were systematically lower than TOMTEC LAS (mean difference -5.76), whereas GE-endo LAS had no systematic bias (mean difference 3.07). Conclusions: Mid-myocardial peak reservoir left atrial strain, which is routinely measured using GE Echopac software, systematically underestimates LAS as compared to TOMTEC LAS or GE endocardial LAS. These systems cannot be used interchangeably for serial follow up of patients.