To evaluate and compare the diagnostic accuracy of three Artificial intelligence (AI) models—GPT-4o, Canva-GPT, and ECG Reader-GPT—against emergency medicine specialists (EMSs) in electrocardiogram (ECG) interpretation using a standardized and validated test set.

In this prospective diagnostic accuracy study, 50 ECG questions were selected from the reference text 150 ECG Cases. Thirty EMSs completed the test once; each AI model was evaluated on the same test set daily over 30 consecutive days. Diagnostic accuracy was compared across predefined ECG subcategories and clinical case types.

EMSs achieved the highest overall diagnostic accuracy (median: 41.5; IQR: 37.0–43.0), followed closely by ECG Reader-GPT (median: 39.5; IQR: 39.0–41.0), with no statistically significant difference between them (p = 0.530). ECG Reader-GPT significantly outperformed both GPT-4o and Canva-GPT across all case categories (p < 0.001). Subgroup analysis revealed that ECG Reader-GPT performed comparably to EMSs in identifying ischemic syndromes, channelopathies and genetic syndromes, and normal ECGs (all p < 0.05); it surpassed them in interpreting rhythm disorders (p = 0.007).

ECG Reader-GPT, a customized AI model for ECG interpretation, demonstrated diagnostic accuracy comparable to experienced EMSs and significantly outperformed general-purpose models across all ECG subcategories. These findings highlight the value of domain specialization in developing clinically effective AI tools.