Knowledge level of ECG interpretation on STEMI, its equivalents and mimics among emergency department medical officers: a single-centre study

Background Accurate electrocardiogram (ECG) interpretation is essential in emergency care, particularly for recognising ST-segment elevation myocardial infarction (STEMI), STEMI equivalents, and STEMI mimics. These patterns guide reperfusion decisions and early management, yet the evolving myocardial infarction paradigm has increased interpretive complexity. This study aimed to assess the ECG interpretation knowledge of STEMI, STEMI equivalents, and STEMI mimics among medical officers in the Emergency Department (ED) and to identify factors associated with their performance. Methods A cross-sectional study was conducted among 62 medical officers in a high-volume tertiary ED in Malaysia (approximately 110,000 annual attendances). Participants completed a validated questionnaire comprising sociodemographic data, training background, and a 20-item ECG assessment focused on STEMI, STEMI equivalents, and mimics. Each ECG was scored dichotomously, and total scores were categorised using Bloom’s cut-off values: poor (< 60%), moderate (60–79%), and good (≥ 80%). Simple logistic regression was used to screen associated variables (p < 0.25), followed by multiple logistic regression to identify independent predictors (p < 0.05). Results Most respondents demonstrated poor ECG interpretation knowledge (71%), while 29% achieved moderate scores; none attained a good level. At item level, participants performed better in identifying classical STEMI patterns but showed low accuracy for STEMI equivalents (e.g., posterior myocardial infarction, Smith-Modified Sgarbossa criteria) and mimics (e.g., pericarditis, benign early repolarisation, left ventricular aneurysm). In an exploratory multiple logistic regression analysis, two possible associations were observed: a 6–12-month interval between graduation and employment showed a possible association with higher odds of moderate knowledge (AOR 7.57, 95% CI 1.57–36.57, p = 0.012), and working experience of 2–5 years showed a possible association with lower odds of moderate knowledge compared with > 5 years of experience (AOR 0.19, 95% CI 0.04–0.96, p = 0.045). ECG course attendance, frequency, timing, confidence level, and number of ECGs interpreted per week were not significant predictors. Conclusions This single-centre exploratory study identified important gaps in the recognition of STEMI equivalents and mimics among ED medical officers. A 6–12-month interval between graduation and employment and more than 5 years of working experience showed possible associations with moderate knowledge; however, given the cross-sectional design, modest sample size, and wide confidence intervals, these findings are hypothesis-generating and should not be interpreted as evidence of causation. The results highlight a critical need for targeted training interventions focusing on high-risk, under-recognised ECG patterns to strengthen diagnostic accuracy and improve patient outcomes in the emergency care setting.