Left ventricle functions evaluated with tissue doppler echocardiography (TDE) after antegrad and antegrade combined with retrograde cardioplegia administration ın coronary artery bypass graft (CABG) procedure

In the course of the historical development of cardiovascular surgery, myocardial protection remains the most dwelled on subject. In comparison to the past, improvement of open heart surgery depends on not only growing surgical experience but also advancements in Coronary Artery Bypass Graft (CABG) techniques and myocardial protection techniques. The frequency of high-risk operations is increasing day by day. Inefficacy of myocardial protection in high-risk patient groups (emergency, re-operation, left ventricle dysfunction) can be a significant cause of mortality and morbidity. Therefore clinical trials are still designed to improve myocardial protection techniques and approaches. In our study, we aimed to evaluate and compare whether antegrade and antegrade combined with retrograde continuous infusion of cold oxygenated blood cardioplegia in order to obtain myocardial protection in patients underwent coronary artery bypass graft surgery with fair and good ventricle function by the use of tissue doppler echocardiography. Tissue Doppler Echocardiography was performed on pre-operative period, post-operative first week and post-operative first month on patients enrolled in the study. In keeping with modified Simpson's rule, left ventricular diastolic and systolic volume, ejection fraction, isovolumic contraction time(ICT), isovolumic relaxation time(IVRT), ejection time(ET), mitral valve diastolic flow waves(E wave, A wave, E/A,EDT) and myocardial performance index were evaluated. In addition, mitral annular velocity assessed by Doppler tissue imaging at different sites of the left ventricle(lateral and septal ); and early diastolic (Em), late diastolic (Am) and Mitral annular peak systolic velocity (Sm) from basal and annular segments of each region were evaluated. The ratio between mitral inflow early diastolic velocity(E) and early diastolic velocity obtained from myocardial segments and mitral annulus was calculated separately for each region and segment. This study was performed on 40 patients undergoing coronary artery bypass graft (CABG) procedure due to coronary artery disease in Zonguldak Bülent Ecevit University Practice And Research Hospital. Tissue Doppler Echocardiography (TDE) was performed on all 40 patients preoperatively. Patients divided in to two groups: 20 patients receiving only antegrade cardioplegia and 20 patients receiving antegrade cardioplegia and retrograde cardioplegia. Tissue Doppler Echocardiography (TDE) was performed at first week and first month post-operatively. The data obtained were compared. Preoperative, postoperative 1st week and postoperative 1st month Tissue Doppler Echocardiography results were compared amongst the two patient groups. Although, transmitral early diastolic velocity (E), as an indicator of global systolic and diastolic functions, E/A rate, ejection fraction (EF), isovolumic relaxation time (IVRT), isovolumic contraction time(ICT), myocardial performance index (MPI), transmitral late diastolic velocity (A), E-wave deceleration time (EDT) and ejection time(ET) assessments were not statistically significant between two groups(p>0.01); changes over time were statistically significant in both groups of patients. When preoperative results were compared with postoperative Tissue Doppler Echocardiography results; there was no statistically significant increase in E, E/A, EF, IVRT, ICT and MPI (p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001; respectively), however, there was a statistically significant decrease in A, EDT and ET (p=0.030, p<0.001, p<0.001; respectively). According to the segmental analysis performed by tissue doppler technique, there was a statistically significant decrease in postoperative Em/Am values (p=0.01). However, there was no statistically significant changing in Sm values (p=0.280). These changes were similar in every assessed region of myocardial wall (basal and annulus of septum; basal and annulus of lateral). Amongst all assessed segments, there was no statistically significant difference in postoperative 7th day compared with postoperative 30th day in terms of evaluated values. As a result of our study, we found that revascularization provided with Coronary Artery Bypass Graft (CABG) Procedure has favorable effects on systolic and diastolic functions of heart, left ventricle functions and transmission system. However, in between two groups(patient group receiving only antegrade cardioplegia versus patient group receiving antegrade cardioplegia and retrograde cardioplegia), there was no statistically significant difference in terms of favorable effects on systolic and diastolic functions of heart, left ventricle functions and transmission system.