Ventricular interaction in children after repair of tetralogy of Fallot: a longitudinal echocardiographic study

Abstract

Progressive right ventricular (RV) dilation due to pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) may impair left ventricular (LV) filling. Our aim was to analyse long-term time courses of M-mode LV and RV measurements and to relate these to the degree of PR. Retrospective longitudinal cohort of children (n = 88) after repair of TOF followed by serial echocardiography over 9 years. LV and RV diameters were expressed by z-scores based on normal paediatric reference values. Time courses of LV and RV diameter z-scores, degree of PR, and influence of co-variables were analysed using mixed regression models. LV diameter z-scores were significantly lowered before repair, increased after surgery, but fell again over time; thus, mean LV diameters were significantly lower than normal population means at all times. LV diameter z-scores correlated negatively with RV dilation and degree of PR. Notably, they were significantly higher in patients with previous shunts. After pulmonary valve replacement, LV diameter z-scores recovered to normal, whereas RV diameter z-scores remained abnormal. Our results confirm progressive adverse RV-LV interaction in the long-term post-operative follow-up of TOF. The use of z-scores facilitated the analysis of time courses of LV and RV diameters.