RIGHT-VENTRICULAR PERFORMANCE AND MASS BY USE OF CINE MRI LATE AFTER ATRIAL REPAIR OF TRANSPOSITION OF THE GREAT-ARTERIES

Background The long-term adaptation of the right ventricle after atria l repair of transposition of the great arteries (TGA) remains a subjec t of major concern. Cine magnetic resonance imaging (MRI), with its to mographic capabilities, allows unique quantitative evaluation of both right and left ventricular function and mass. Our purpose was to use M RI and an age-matched normal population to examine the typical late ad aptation of the right and left ventricles after atrial repair of TGA. Methods and Results Cine MRI was used to study ventricular function an d mass in 22 patients after atrial repair of TGA. Images were obtained in short-axis sections from base to apex to derive normalized right a nd left ventricular mass (RVM and LVM, g/m(2)), interventricular septa l mass (IVSM, g/m(2)), RV and LV end-diastolic volumes (EDV, mL/m(2)), and ejection fractions (EF). Results 8 to 23 years after repair were com-pared with analysis of 24 age- and sex-matched normal volunteers a nd revealed markedly elevated RVM, decreased LVM and IVSM, normal RV s ize, and only mildly depressed RVEF. Only 1 of 22 patients had clinica l RV dysfunction, and this patient had increased RVM. Conclusions Cine MRI allows quantitative evaluation of both RV and LV mass and functio n late after atrial repair of TGA. Longitudinal studies that include t hese measurements should prove useful in determining the mechanism of late RV failure in these patients. On the basis of these early data, i nadequate hypertrophy does not appear to be the cause of late dysfunct ion in this patient group.