Evaluation of myocardial function in pediatric patients with transposition of great arteries after arterial switch operation

OBJECTIVE An arterial switch operation converts the left ventricle (LV) into the systemic ventricle, replacing the right ventricle (RV), which is the systemic ventricle during the prenatal period. The procedure is performed in patients with arterial transposition and those in whom a coronary reimplantation procedure is performed. Therefore, the adaptation of LV and RV to the arterial switch operations is an interesting issue. This study aimed to evaluate systolic and diastolic functions in the LV and RV myocardium using echocardiography in pediatric patients with transposed great arteries after an arterial switch operation. METHODS This observational case control study included 28 patients and 20 gender-and age-matched healthy controls. A group study was performed using patients who were followed for at least 6 months after the operation and who visited the pediatric cardiology outpatient between October 2009 and May 2011. Systolic and diastolic parameters, LV and RV myocardial performance index (MPI) values, and left atrium (LA) volume index were assessed in both groups. RESULTS The LV MPI and tricuspid valve (TV) E/Ea ratio measured using pulsed-wave Doppler were higher in the patient group than in the control group. The TV E/A ratio and late velocity of lateral mitral annulus (Aa) and systolic velocity (Sa)-early diastolic velocity (Ea)-late velocity (Aa) of the septal mitral annulus and systolic velocity (Sa)-early diastolic velocity (Ea)-late velocity (Aa) of the lateral tricuspid annulus were lower in the patient group than in the control group. CONCLUSION Considering the present study's findings obtained during short-to mid-term follow-up, the RV tissue Doppler flows and the LV MPI were found impaired.