Assessment The Changes Of Left Ventricular Global And Regional Systolic Function In Patients Before And After Coronary Artery Bypass Grafting Using Real-time Three-dimensional Echocardiography

Background Coronary artery disease (CAD) is a very common cardiovascular disease. Its prognosis is close related with left ventricular (LV) function. Coronary artery bypass surgery, a treatment of CAD, is increasingly being performed on the beating heart. However, both M mode and two dimensional echocardiography(2DE) make important geometric assumptions about the LV which leads to inaccuracies in measurements. Real-time three-dimensional echocardiography (RT-3DE), as a novel technique, overcomes the geometric limitations of M mode and 2DE. RT-3DE is an ideal tool for the measurement of LV volume because no geometric assumptions about LV shape are needed. Therefore, it could obtain accurate result although LV cavity is deformed or its wall motion is abnormal.Objective To assess the changes of left ventricular global and regional systolic function in patients with CAD before and after off-pump coronary artery bypass grafting (OPCABG) using RT-3DE.Methods 30 patients with CAD who would all undergo vessel grafted of left internal mammary artery grafting to the left anterior descending coronary artery (LAD) were collected. All patients before and after OPCABG and 20 healthy subjects were all tested by RT-3DE. Images were analyzed with Q-LAB 5.0 software offline. Global left ventricular (LV) end-diastolic volume (EDV), LV end-systolic volume (ESV), LV ejection fraction (EF), peak ejection rate (PER), PER/EDV were measured and calculated. And the regional LV end-diastolic volume (rEDV), end-systolic volume (rESV) and ejection fraction (rEF) of the segmental walls domained by LAD were also measured and analyzed.Results Compared with patients before OPCABG, EDV and ESV decreased(P<0.05), EF and PER/EDV increased (P<0.05), rEDV and rESV decreased, rEF increased in patients after OPCABG. Compared with healthy subjects, EDV and ESV increased (P<0.05), EF and PER/EDV decreased (P<0.05), rEDV and rESV increased, rEF decreased in patients before and after OPCABG. There was positive correlation between EF and PER/EDV(r=0.603, P<0.05). There was no significant difference in PER among health subjects, patients before and after OPCABG. Conclusion RT-3DE can assess the changes of global and regional systolic function of left ventricle before and after OPCABG in patients with CAD. Left ventricular dilation and depression of global and regional ejection fraction have been detected in patients with CAD. After OPCABG, the volumes have declined, global and regional ejection fractions of left ventricle have improved in early. PER/EDV derived from volume-time curve is a new parameter to assess systolic function of left ventricle.