Alteration Of Left Ventricular Diastolic Function During Off-pump Coronary Artery Bypass And Its Clinical Significance

Objective Evaluation of left ventricular diastolic function during off-pump coronary artery bypass and to investigate its clinical significance by using Doppler echocardiography. Methods We studied 48 patients with coronary artery disease before and after 1 week and 3 months off-pump coronary artery bypass, and 35 healthy volunteers matched with age. From the apical four chamber view, the image of mitral inflow was obtained and early diastolic peak flow velocity (E), late diastolic peak flow velocity (A), the ratio of E/A and deceleration time of E wave (DT) were measured. Left ventricular early diastolic flow propagation velocity (Vp) was measured by color M-mode Doppler from the apical four chamber. The early diastolic peak myocardial motion velocity (Eμ), late diastolic peak myocardial motion velocity (Am), the ratio of Eμ / Am, systolic peak myocardial motion velocity (Sμ) and displacement (Ds) and electrocardiogram Q wave to onset of Sμ (Q- Sμ) were measured by tissue Doppler imaging. Results Compared with control group, the E of OPCAB group was decreased (P<0.01), E/A was decreased (p<0.05), A was increased (P<0.01). There was no difference in DT. Vp was decreased (P<0.01). Eμ and Em/Am were decreased (P<0.01). There was no difference in Am- Sμ and Ds were decreased (P<0.01). Q-Sm was increased (P<0.05). Multinomial linear regression analysis showed that age, LVESVI and EF were determinant to VP (b'=-0.17, -0.36, 0.33, r=-0.16, -0.32, 0.34, P<0.05). There were no change in E, A, E/A and DT before and after OPCAB. Vp was improved in the early stage after OPCAB and further improved after 3 months OPCAB, respectively (F=6.01, P<0.01). Eμ and Em/Am were increased after OPCAB (P<0.01). there was no change in AM (p>0.05) .Sμ and DS were increased after OPCAB (P<0.01), Q-SM was decreased after OPCAB (P<0.01). Conclusions Left ventricular diastolic function was improved after OPCAB. Combined with mitral flow imaging, VP and TDI can evaluate left ventricular diastolic function accurately before and after OPCAB.