RIGHT-VENTRICULAR AND LEFT-VENTRICULAR PERFORMANCE 10 YEARS AFTER MUSTARD REPAIR OF TRANSPOSITION OF THE GREAT-ARTERIES

Twenty-two late survivors of Mustard repair of transposition of the gr eat arteries underwent treadmill exercise testing to assess exercise e ndurance, and radionuclide cineangiography to measure rest and exercis e right ventricular (RV) and left ventricular (LV) ejection fraction ( EF). Mean age at Mustard repair was 1.8 +/- 2.4 years and at initial e xercise study 14.1 +/- 4.5 years. All patients were asymptomatic at st udy entry. Treadmill endurance time (9 to 12 minutes) was within the n ormal range for age in 18 of 20 patients. LVEF and RVEF at rest were w ithin normal limits (55 +/- 8% and 52 +/- 9%, respectively). All LVEFs and RVEFs during exercise were also within the normal range (64 +/- 8 % and 57 +/- 9%, respectively). However, the magnitude of increase in EF (rest to exercise) was subnormal for the right ventricle in 1 patie nts and for the left ventricle in 2 patients. Exercise RVEF was higher in patients with simple transposition who underwent repair at <1 year of age than in those who underwent operation at age >1 year (62 +/- 1 0% vs 52 +/- 7%). Serial study in 6 patients revealed no change in ave rage RVEF or LVEF after an average interval of 4.4 years. One patient with complex transposition subsequently developed refractory congestiv e heart failure requiring cardiac transplantation. It is concluded tha t exercise endurance and LVEF and RVEF at rest and exercise are genera lly well preserved up to 19 years after Mustard repair, particularly i n cases of simple transposition of the great arteries repaired before 1 year of age.