1066 Analysis of the systemic right ventricle (RV) in patients after atrial switch operation for the correction of complete transposition of great arteries (d-TGA) by MRI

Abstract

PurposeTo determine morphologic and functional alterations of the systemic ventricle in patients after atrial switch operation for the correction of complete transposition of the great arteries (d-TGA). Right (RV) and left ventricular (LV) volumes were compared with those of normals. MethodsMRI examinations were performed in 37 patients (24 male and 13 female) after Mustard/Senning-operation (MSO-atrial switch) to correct d-TGA. A complete set of short axis slices were acquired using steady state free precession sequences on a 1,5 T-scanner (Gyroscan ASC-NT, PowerTrak 6000, Philips). RV and LV parameters were compared between the patient group and normal values. ResultsCompared to normal values (26 ± 5 g/m 2 ) right ventricular muscle mass of MSO-patients (43.6 ± 16.2 g/m 2 ) was significantly higher. The stroke volume of patients (33.8 ± 10.4 ml/m 2 ) was significantly lower compared to controls (46 ± 8 ml/m 2 ). The mean RV ejection fraction of patients (43,6 ± 9%) was also decreased (normal value: 43-63%). Patients with a stronger hypertrophy of the RV (>40 g/m 2 ) had a significant higher ejection fraction and a significant lower enddiastolic volume than those with RV muscle mass within normal values (<40 g/m 2 ) (Fig. 1). Comparing the RV (systemic ventricle) of patients and the LV of controls (systemic ventricle) a significant lower muscle mass was found in patients (43,6 ± 16,2 g/m 2 vs. 87 ± 12 g/m 2 ). We also found a significant lower ejection fraction (43,6 ± 9%) and a significant lower stroke volume (33,8 ± 10,4 ml/m 2 ) in patients compared with controls.