Automated quality indicators for echocardiographic recordings and measurements: consequences for left ventricular global longitudinal strain.

AIMS: Global longitudinal strain (GLS) is a sensitive measure of left ventricular (LV) function, though hampered by significant variability. Data on how echocardiographic recordings and measurements influence GLS and its variability are scarce. We aimed to study the consequences of variability in echocardiographic recordings and measurement procedures for GLS in a normal population. METHODS AND RESULTS: Healthy participants (n = 1412) from the Trøndelag Health Study were examined by echocardiography according to current recommendations. Four experienced operators read and re-read all GLS recordings (2824 measurement procedures). Characteristics of echocardiographic recordings and measurement procedures were extracted by deep learning (DL) and software metadata.LV apical endocardium was positioned at a mean distance of 26 mm from the top of the sector and 6 mm to the left of the central axis. Mean LV foreshortening ranged 1.2-2.1 mm in apical views and the recordings were well standardized with the preferred cut-planes for tilt and rotation. GLS (in percentage points) was lower with reduced image quality (0.8), longer LVs (0.2 per cm), wider regions of interest (0.8 per mm) during the measurement procedure, and longer distance (0.07 per mm) from the transducer to the LV apex, respectively. Moreover, GLS was 0.7 percentage points higher per mm apical foreshortening, and also higher when a more refined ROI initialization was used. CONCLUSION: Using novel DL methodology and available metadata, we found that indicators of image standardization and measurement procedures influenced GLS. Implementing such quality indicators during recording and measurement procedures may improve the efficacy of echocardiography and ease the interpretation of differences between studies.