Value of Low-Dose Dobutamine Stress Real-Time Myocardial Contrast Echocardiography in the Diagnosis of Coronary Heart Disease

To investigate the value of low-dose dobutamine stress real-time myocardial contrast echocardiography (RT-MCE) in the diagnosis of coronary heart disease (CHD). A total of 65 hospitalized patients with suspected or confirmed CHD were detected by RT-MCE combined with low-dose dobutamine stress (0.84 mg/kg). Perfusion curves were quantitatively analyzed using QLAB software. Peak intensity (A), slope of curves (beta), and perfusion (A x beta) were also calculated. Based on the results of coronary angiography, patients were divided into no obvious stenosis group (<50%), mild stenosis group (50%-74%), moderate stenosis group (75%-89%), and severe stenosis group (>= 90%). The A, b, and A x beta values before and after low-dose dobutamine stress of each group were compared. In the basal state and after low-dose dobutamine stress, the A, b, and A x beta values significantly decreased as the stenosis degree of the myocardial segments increased. The same variation tendency was also found in the A x beta, and A x beta reserve values, and there was significant difference in these reserve values between moderate and severe stenosis groups and no obvious stenosis and mild stenosis groups. Collateral circulation had marked effects on the values of myocardial perfusion parameters and their reserve values, especially in the segments with severe stenosis. Low-dose dobutamine stress RT-MCE can be a sensitive method for clinical diagnosis and risk assessment of CHD and may provide a basis for further treatment of CHD.