| Complete transposition of the great arteries (TGA) is one of the most common cyanotic congenital heart diseases seen in newborns, just second only to Tetralogy of Fallot, represent 7-9% of all congenital heart diseases, corresponding to an incidence of 2 to 3 per 10000 live births.There is a male predominance with a male/female sex ratio that approximately 2:1. In this defect, the aorta arises from the morphological right ventricular, and the pulmonary artery arises from the morphological left ventricular. This disease is very complex, and the natural survival rate is very low, the mortality rate in untreated patients is approximately 90% by the end of the first year.The primary treatment for complete transposition of the great arteries is surgical repair. The surgical procedures includes:the atrial switch operation and the arterial switch operation. The atrial switch operation includes Mustard and Senning procedures, but these procedures just give physical correction for complete transposition of the great arteries.Long-term follow up is mainly influenced by arrhythmias, tricuspid regurgitation, right ventricular dilatation, systolic dysfunction of the systemic right ventricle in patients with complete transposition of the great arteries after Mustard and Senning procedures, some studies have reported that reduced function of the systemic right ventricle is associated with increased mortality in late stage outlook of these patients. With recent improvement in surgical technique and postoperative care, atterial switch operation is currently the procedure of the best choice for neonates with complete transposition of the great arteries, compared with atrial switch operation, the primary adventages of the arterial switch operation is not only establishment of left ventricle as the systemic ventricle, but also given physical correction for complete transposition of the great arteries. Accurate evaluation of left and right ventricular function in preoperative and postoperative patients with transposition of great arteries, can help to select timing for surgical operation select surgical procedure,assess operative outcomes and prognosis. Currently, echocardiography is the preferred method for clinical evaluation of left ventricular function, the left ventricular ejection fraction (LVEF) is the most common measurement parameter of left ventricular function, using echocardiography in evalution of left ventricular function is substantially perfect. However, assessing the function of the morphological right ventricle by conventional echocardiography is inherently difficult. Severial imaging modalities, such as cardiac magnetic resonance imaging, angiography are the gold standard for accurate quantitative evaluation of right ventricular function, but these technology are not available for neonates. A recent developed ultrasound speckle tracking imaging (STI) technique can trace the speckle spatial motions of myocardium and calculate deformation of the myocardial tissue, and then give accurate quantitative assessment of reginal myocardial function and ventricular globe function, so the STI technique can detect the regional dysfunction of ventricular before the globe dysfunction of ventricular, and it also have been used to assess right ventricular function widely. But so far, there are no reports to evaluate the right function with complete transposition of the great arteries after aterial switch operation by using ultrasound speckle tracking imaging, so the present study was divided into three parts as follows: Part 1 Assessment of right ventricular regional and global function in patients with complete transposition of the great arteries by ultrasound speckle tracking imagingObjective:Assessment of right ventricular (RV) regional and global function in patients with complete transposition of the great arteries by ultrasound speckle tracking imaging.Methods:There were 25 patients with complete transposition of the great arteries enrolled in our study,19 males and 6 females. The TGA patients were divided into intact ventricular septum TGA (14 cases) and ventricular septal defect TGA(11 cases) according to the complete of the ventricular septal.16 cases of normal control group were chosen in our study. Two-dimensional strain (2DS) were obtained at the apical four-chamber views and then were analyzed offline by using automated software (EchoPAC,GE Medical). The myocardial logitudinal peak systolic stain were determined at the basal, mid, and apical segment of the righe ventricular free wall and ventricular septum by 2DS, the right ventricular global logitudinal peak systolic stain were also determined by 2DS.Compare the data between three groups. Besides, measuring RV end-diastolic dimension (RVED), RV ejection fractions (RVEF), RV percent change in area (RVPCA) and tricuspid annular systolic peak velocity (TVSPV), and analyzing correlation of these parameters with RV global logitudinal peak systolic stain.Results:â‘ The right ventricular longitudinal peak systolic strain (S), strain rate (SR) of basal, mid, apical segment in free wall were lower in TGA patients compared with normal controls,the difference was significant (P<0.05). The right ventricular longitudinal S of basal, mid, apical segment in interventricular septum were lower in TGA patients compared with normal controls (P<0.05). The SRs of apical of interventricular septum were lower in TGA/IVS patients compared to controls (P<0.05). The SRs of basal, mid in interventricular septum in TGA/IVS patients and all sigments in interventricular septum in TGA/VSD patients were slightly reduced compared with controls,the difference was no significant.(P>0.05).â‘¡The right ventricular GLS,GLSRs and GLSRe in TGA/IVS patients were lower than controls, the difference was significant (P<0.05). The right ventricular GLSRa was slight reduced compared with controls, the difference was no significant(P>0.05). The right ventricular GLS,GLSRs in TGA/VSD patients were lower than controls(P<0.05). The GLSRa were slightly reduced compared with controls(P>0.05).â‘¢All the strain parameters in TGA/IVS patients were lower than TGA/VSD patients, but the difference was no significant (P>0.05).â‘£The TVSPV had correlation with right ventricular GLS in TGA/IVS patients (r=0.66, P<0.05), and also had correlation with right ventricular GLSRs in TGA/VSD patients (r=-0.75, P<0.05)Conclusion:The right ventricular regional and global function reduced in patients with complete transposition of the great arteries. Ultrasound speckle tracking imaging technique can quantitatively assess the right ventricular regional and global function accurately. Ultrasound speckle tracking imaging is an effectively methods for evaluating right ventricular function. Part 2 Assessment of right ventricular regional and global function in preoperative and early period of postoperative patients with complete transposition of the great arteries after arterial switch operation by ultrasound speckle tracking imagingObjective:Assessment of right ventricular regional and global function in preoperative and early period of postoperative patients with complete transposition of the great arteries after arterial switch operation by ultrasound speckle tracking imaging.Methods:There were 25 patients with complete transposition of the great arteries enrolled in our study,19 males and 6 females.16 cases of normal control group were chosen in our study. The TGA patients were divided into 14 cases of intact ventricular septum TGA and 11 cases of ventricular septal defect TGA according to the complete of the ventricular septal. Such indexes were measured by STI before operation,2 weeks after operation,3 months after operation separately, the myocardial logitudinal peak systolic stain were determined at the basal, mid, and apical segment of the righe ventricular free wall and interventricular septum by 2DS, the right ventricular global logitudinal peak stain were also determined by 2DS.Results:â‘ The right ventricular GLS,GLSRs and S,SRs of all the segments in right ventricular free wall in TGA/IVS patients reduced compared with the controls. These indexes gradually increased 2 weeks and 3 months after operation, but still below normal levels. But, the right ventricular GLSRs and SRs of all the segments in right ventricular free wall increased to normal levels; S,SRs of all segments in right ventricular interventricular septum were lower compared with normal controls before operation, S,SRs of basal segment in right ventricular interventricular septum further reduced compared with preparation 2 weeks after operation, and gradually increased 3 months after operation., the SRs increased to normal level, but S was still lower than normal levels. S,SRs of mid,apical segments in right ventricular interventricular septum, gradually increased 2 weeks and 3 months after operation. S was still lower than normal level, but SRs increased to normal level.â‘¡The GLS,GLSRs of the right ventricular and the right ventricular S, SR of all segments in free wall were lower in TGA/VSD patients compared with normal controls, but these indexes gradually decreased 2 weeks and 3 months after operation, S of all segments in right ventricular free wall were lower in 2 weeks after operation than before operation, increased in 3 months after operation, were lower than before operation, but was still lower than normal levels. SRs of basal segment in right ventricular free wall increased gradually to normal levels 2 weeks and 3 months after operation. SRs of mid,apical segments in right ventricular free wall were still at the preoperative level, however, S,SRs of all segments in right ventricular interventricular septum were lower than preoperative level, and gradually reduced compared with preoperative level.Conclusion:The right ventricular regional and global function increased in TGA/IVS patients at early period after arterial switch operation. The regional ventricular function increased slightly in TGA/VSD patients, but the global ventricular function were still at the preoperative level. STI technique can quantitatively assess the right ventricular regional and global function accurately and it also can detect the changes of cardiac function early and sensitively. In a word, STI can provide important value for clinical evaluation of surgical treatment and prognosis. Part 3 Assessment of right ventricular regional and global function in patients with complete transposition of the great arteries at least one year after arterial switch operation by ultrasound speckle tracking imagingObjective:Assessment of right ventricular regional and global function in patients with complete transposition of the great arteries at least one year after arterial switch operation by ultrasound speckle tracking imaging.Methods:There were 20 patients with complete transposition of the great arteries enrolled in our study,17 males and 3 females.16 cases of normal control group were chosen in our study. The TGA patients were divided into 10 cases of intact ventricular septum TGA and 10 cases of ventricular septal defect TGA according to the complete of the ventricular septal. Two-dimensional strain (2DS) were obtained at the apical four-chamber views and then were analyzed offline by using automated software (EchoPAC,GE Medical). The myocardial logitudinal peak systolic stain were determined at the basal, mid, and apical segment of the righe ventricular free wall and ventricular septum by 2DS, the right ventricular global logitudinal peak systolic stain were also determined by 2DS.Compare the data between three groups. Besides, measuring RV end-diastolic dimension (RVED), RV ejection fractions (RVEF), RV percent change in area (RVPCA) and tricuspid annular systolic peak velocity (TVSPV), and analyzing correlation of these parameters with RV global logitudinal peak systolic stain.Results:â‘ There were not only no differences of S,SRs of all the segments in the right ventricular free wall and interventricular septum in TGA/IVS patients compared to normal controls after arterial switch operation(P>0.05), but also no differences of the right ventricular GLS,GLSRs,GLSRe. GLSRa in TGA/IVS patients compared to normal controls (P>0.05).â‘¡The SRs of basal,mid segment in right ventricular free wall in TGA/VSD patients reduced after artrial swith operation, the difference was significant (P<0.05). There was no significant difference of the SRs of apical segment in right ventricular free wall compared with controls (P>0.05).There were no significant differences of the S of all the segments in right ventricular free wall and interventricular septum compared with normal controls (P>0.05); The right ventricular GLSRs,GLSRe. GLSRa in TGA/VSD patients reduced compared with normal controls, the difference was significant (P<0.05), but the difference of right ventricular GLS compared with normal controls was not significant (P>0.05)Conclusion:The right ventricular regional and global function returned to normal level in TGA/IVS patients after arterial switch operation for more than 1 year. The right ventricular regional and global function reduced slightly in TGA/VSD patients compared with normal controls after arterial switch operation for more than 1 year. STI technique can detect the function changes of right ventricular regional and global function early and sensitively. STI provide a new method for clinical evaluation of right ventricular function. |
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