Introduction
DM is a systemic metabolic disorder, and more than 70% of diabetic patients develop coronary heart disease (CHD), which exhibits a wider range and faster progression of coronary artery disease compared to non-diabetic individuals. The main lesions in CHD occur in the epicardium, whereas in DM, the primary lesions involve the myocardium and microvasculature. When both conditions coexist, the aforementioned lesions may be more extensive and severe. Clinical observations have shown that DM patients with concomitant CHD have a higher prevalence and severity of multi-vessel and diffuse coronary lesions compared to non-diabetic patients[1-2]
Studies have confirmed that after acute myocardial infarction (AMI), the region of RWMA comprises not only necrotic myocardium but also viable myocardium, including stunned myocardium and hibernating myocardium[3-4]. So far, there are three main approaches used to identify viable myocardium[4]: (1) Assessment of myocardial cellular metabolism, including oxidative metabolism, glucose metabolism, and fatty acid metabolism; (2) Evaluation of myocardial perfusion; (3) Monitoring of myocardial contractile reserve. Among these, dobutamine stress echocardiography (DSE) is internationally recognized as the standard method for monitoring myocardial contractile reserve and is widely employed.
At present, STE-LDDSE offers significant advantages over traditional methods for assessing viable myocardium[5-8]. It mainly tracks the speckles of high-frame-rate two-dimensional images frame by frame, allowing for the calculation and delineation of myocardial motion velocity and deformation. By observing myocardial motion trajectories, it accurately measures myocardial fiber motion strain, strain rate, and rotation angles. Due to its angle-independent nature, STE can provide more accurate assessments of local and global myocardial function, making it highly valuable for detecting viable myocardium. The combination of STE and LDDSE further enhances the sensitivity and specificity, maximizing the detection of viable myocardium[9-12].