Figure 1.

Inclusion-exclusion flowchart for the New England study population. Exclusion criteria for transthoracic echocardiography (TTE) studies and videos included in this study from the Yale-New Haven Health network. Studies with valid pixel data were de-identified frame by frame, and the parasternal long axis (PLAX) view was determined by an automated view classifier. A sample of 12 500 studies from 2016 to 2020 were split into a derivation set and external test set, which comprised studies from hospital sites not encountered during model development. An independent random sample of 2500 studies from 2021 was used as an additional test set to evaluate robustness to temporal shift