Effect of sequential coronary artery bypass venous grafting on right ventricular functions assessed by tissue Doppler echocardiography

Abstract

Background: Coronary artery bypass graft surgery is a well-known and proven method of treatment for coronary artery disease. A modification of this method is complete revascularisation of the right ventricle by sequential bypass grafting of the right coronary artery, the effects of which on ventricular function need to be clarified. We sought to determine the effect of the sequential bypass graft method on right ventricular (RV) function utilising tissue Doppler echocardiography. Methods: A total of 35 coronary artery disease patients (group A: 20 sequential grafts; group B: 15 individual grafts) were enrolled. Patients were examined pre-operatively with tissue Doppler echocardiography for RV function, and again postoperatively after the first month. Results: Pre-operatively, there were no significant differences with regard to demographics or basal echocardiographic findings. On the other hand, postoperative right ventricular diastolic function was found to have improved significantly as the right ventricular E wave and E/A increased (9.5 +/- 1.6 vs 7.6 +/- 2.7 cm/s, p = 0.009 and 1.4 +/- 0.2 vs 0.9 +/- 0.2, p = 0.01, respectively), while the A wave and isovolumic relaxation times (6.8 +/- 2.1 vs 8.3 +/- 3.4 cm/s, p < 0.03 and 55.2 +/- 11.9 vs 87.2 +/- 16.2 ms, p < 0.001, respectively) decreased. Although the S-wave peak amplitude decreased in group A patients, it did not reach statistical significance. Conclusions: Sequential, but not single, complete revascularisation of the right coronary artery appeared to improve the diastolic function of the right ventricle.