RESUMO
Pulmonary valve regurgitation is the most common complication after complete repair of tetralogy of Fallot. The benefits of pulmonary valve replacement (PVR) on right ventricular (RV) volumes is well established. However, the effect on left ventricular (LV) function is still debated. We aimed to determine the evolution of LV function after PVR and assess the contribution of the interventricular septum (IVS) motion. A total of 21 patients (mean age 30.1 ± 14.1 years) presenting with a history of complete repair of tetralogy of Fallot and requiring PVR prospectively underwent cardiac magnetic resonance imaging before and after PVR to measure the end-diastolic volume (EDV), end systolic volume, and ejection fraction for the LV and RV chambers. Maximal excursion of the IVS was also calculated to quantify abnormal septal motion. The LV-EDV and LV-end systolic volume was 80 ± 27 and 40 ± 19.5 ml/m(2) before PVR and 81.5 ± 23 and 35 ± 14 ml/m(2) after PVR, respectively, leading to a significant increase in LV ejection fraction of 6.1 ± 4.9% (51 ± 8.2% before and 57 ± 6.8% after PVR, p = 0.0003). Also, a significant reduction in RV-EDV (p = 0.0001) and RV end-systolic volume (p = 0.0001) was seen but without improvement in the RV ejection fraction. The maximum IVS excursion decreased after PVR (9.2 ± 3.4 mm before and 6.8 ± 3.6 mm after; p = 0.002). LV ejection fraction improvement correlated with RV-EDV before PVR (ρ = 0.43; p = 0.049). The maximum IVS excursion correlated with RV-EDV before and after PVR but was independent of LV ejection fraction improvement. In conclusion, the results of the present study have demonstrated a significant improvement in LV ejection fraction after PVR that correlated with the pre-PVR RV-EDV but was independent of IVS motion improvement.
