摘要Background Regional ejection fraction (EF_R) measured by real-time three-dimensional echocardiography (RT-3DE)provides a novel method for quantifying left-ventricular (LV) regional systolic function. We aimed to explore the diagnostic value of regional ejection fraction (EFR) derived from RT-3DE in detecting LV aneurysms in patients with myocardial infarction. Methods Thirty-eight patients with myocardial infarction were prospectively enrolled and underwent electrocardiography (ECG), two-dimensional echocardiography (2-DE), RT-3DE and left ventriculography (LVG).Subjects with a negative EFR in at least one segment on RT-3DE were considered as having a ventricular aneurysm. We compared the sensitivity, specificity, Youden's index, and positive and negative predictive values of ECG, 2-DE and RT-3DE in determining LV aneurysm with detection by LVG.Results On LVG an LV aneurysm was diagnosed in 16 (42.1%) patients. The sensitivity and specificity were 62.5% and 86.4% for ECG, 81.2% and 95.4% for 2-DE, and 100.0% and 90.9% for RT-3DE in diagnosing LV aneurysm. Youden's indexes for ECG, 2-DE and RT-3DE were 0.49, 0.77 and 0.91, respectively. Positive and negative predictive values were 76.9% and 76.0% for ECG, 92.9% and 87.5% for 2-DE, and 88.9% and 100.0% for RT-3DE. Conclusions RT-3DE-derived EFR provides a novel, reliable index in the diagnosis of LV aneurysm and has excellent sensitivity and specificity.