Effectiveness of the GPT-4o Model in Interpreting Electrocardiogram Images for Cardiac Diagnostics: Diagnostic Accuracy Study

Background: Recent progress has demonstrated the potential of deep learning models in analyzing electrocardiogram (ECG) pathologies. However, this method is intricate, expensive to develop, and designed for specific purposes. Large language models show promise in medical image interpretation, and yet their effectiveness in ECG analysis remains understudied. Generative Pretrained Transformer 4 Omni (GPT-4o), a multimodal artificial intelligence model, capable of processing images and text without task-specific training, may offer an accessible alternative. Objective: This study aimed to evaluate GPT-4o’s effectiveness in interpreting 12-lead ECGs, assessing classification accuracy, and exploring methods to enhance its performance. Methods: A total of 6 common ECG diagnoses were evaluated: normal ECG, ST-segment elevation myocardial infarction, atrial fibrillation, right bundle branch block, left bundle branch block, and paced rhythm, with 30 normal ECGs and 10 of each abnormal pattern, totaling 80 cases. Deidentified ECGs were analyzed using OpenAI’s GPT-4o. Our study used both zero-shot and few-shot learning methodologies to investigate three main scenarios: (1) ECG image recognition, (2) binary classification of normal versus abnormal ECGs, and (3) multiclass classification into 6 categories. Results: The model excelled in recognizing ECG images, achieving an accuracy of 100%. In the classification of normal or abnormal ECG cases, the few-shot learning approach improved GPT-4o’s accuracy by 30% from the baseline, reaching 83% (95% CI 81.8%-84.6%). However, multiclass classification for a specific pathology remained limited, achieving only 41% accuracy. Conclusions: GPT-4o effectively differentiates normal from abnormal ECGs, suggesting its potential as an accessible artificial intelligence–assisted triage tool. Although limited in diagnosing specific cardiac conditions, GPT-4o’s capability to interpret ECG images without specialized training highlights its potential for preliminary ECG interpretation in clinical and remote settings.