Assessment of right ventricular performance by pulsed doppler echocardiography in patients after intraatrial repair of aortopulmonary transposition in infancy or childhood

Abstract

The purpose of this study was to determine whether measurement of aortic blood flow velocity and acceleration by pulsed Doppler ultrasound can be used to assess the global performance of the systemic right ventricle noninvasively in young patients who have undergone intraatrial repair of aortopulmonary transposition. The effect of age at surgery on right ventricular performance in these patients was also studied. Pulsed Doppler velocity profiles of aortic blood flow were analyzed at a mean age of 5.5 years in 24 patients who had undergone intraatrial repair of aortopulmonary transposition either in early infancy (mean age 3.4 ± 1.3 weeks) or later (mean age 8.5 ± 6.5 months). Velocity and acceleration variables in these patients were compared with the same variables in 24 age-matched normal subjects and with the performance of their own right ventricle as assessed by two-dimensional echocardiographic measurement of ejection fraction.The 12 patients who underwent early repair had a higher ejection fraction than did the 12 who underwent later repair (mean ± SD 0.60 ± 0.07 versus 0.42 ± 0.10; p < 0.001). Aortic flow velocity was similar in all patients. Aortic acceleration was normal in patients after early intraatrial repair of aortopulmonary transposition (20.8 ± 2.3 m/s2), but was abnormally slow in patients after late repair (11.1 ± 1.8 m/s2; p < 0.001), thus suggesting that the latter group had diminished right ventricular performance. Concomitantly, acceleration time and ratio of acceleration time to ejection time were increased in patients after late repair. All three acceleration variables were linearly correlated with right ventricular ejection fraction (r = 0.72, r = 0.63 and r = 0.71, respectively; p <0.001).These findings indicate that measurement of aortic blood flow acceleration by pulsed Doppler ultrasound can be used to assess right ventricular performance noninvasively in patients after intraatrial repair of aortopulmonary transposition. The data also suggest that early intraatrial repair may promote better right ventricular performance.