Objective Left ventricular ejection fraction (LVEF) is measured to assess haemodynamic status and cardiac function. It may be difficult to accurately measure in patients with heart failure (HF) as they are often poorly echogenic. The augmented reality (AR) technology is expected to provide real-time guidance that will enable more accurate measurements.

Methods A prospective, randomised, case-crossover simulation study was conducted to confirm the effect of AR glasses on echocardiographic interpretation in patients with HF. 22 emergency physicians participated. The participants were randomly assigned to two groups. Group A estimated the visual ejection fraction of echocardiographic video clips without the AR glasses, while group B estimated them with glasses. After a washout period, the two groups crossed over. The estimates were then compared with the ejection fraction measurements obtained by echocardiologists; intraclass correlation coefficient (ICC) was calculated.

Results The ICC with glasses (0.969, 95% CI 0.966 to 0.971) was higher than without glasses (0.705, 95% CI 0.681 to 0.727) among all participants. In the subgroup analysis, the first-year and second-year residents showed the most significant difference, with an ICC of 0.568 (95% CI 0.508 to 0.621) without glasses compared with 0.963 (95% CI 0.958 to 0.968) with glasses. For the third-year and fourth-year residents group, the ICC was 0.754 (95% CI 0.720 to 0.784) without glasses and 0.972 (95% CI 0.958 to 0.968) with glasses. Among the group of attending physicians, the ICC was 0.807 (95% CI 0.775 to 0.834) without glasses and 0.973 (95% CI 0.969 to 0.977) with glasses.

Conclusions AR glasses could be helpful in measuring LVEF and could be more helpful to those with little visual estimation experience.