Background and aims: Pulmonary regurgitation (PR) with progressive right ventricle (RV) dilatation is extremely common late after repair of Tetralogy of Fallot (TOF) in childhood. Guidelines recommend pulmonary valve replacement (PVR) when indexed RV end diastolic volume (RVEDVi) exceeds 150 ml/m2, even in asymptomatic patients. As PVR, however, has limited durability, this should be deferred as long as possible.We compared subjects with RVEDVi below versus above this cut-point, measuring haemodynamics and exercise capacity objectively. Methods: Of 60 patients with repaired TOF (mean age at repair 2.6±2.5 years; age at study 24.5±9.5 years; range 11-48; 36 males), 33 had RVEDVi below and 27 had RVEDVi above 150 ml/ m2. Detailed cardiac MRI (1.5T) and cardiopulmonary exercise test (CPET) were performed. Results: Comparing the two groups, there were no significant differences in LV stroke volume (77±4ml vs 86±3 ml, p = 0.06), LV ejection fraction (56±1%vs 56±2%, p = 0.86) or exercise capacity (% predicted Wpeak: 88±3% vs 92±4%, p = 0.50 and; % predicted VO2peak: 88±3% vs 84±3%, p = 0.43). For the group as a whole, fractional PR was 32±15% and bi-ventricular ejection fractions (EF) were maintained (LV: 57±7% and RV: 50±7%). Fibrosis was rarely detected in the RV body (n = 1) and more frequently in the RVOT (n = 33, no difference between groups). Conclusions: Exercise capacity, stroke volume and biventricular contractile function were maintained with RVEDVi above compared to below the currently recommended cut-off for PVR surgery. Optimal timing for PVR thus remains unclear, given these observations.
O’Meagher, S., Celermajer, D., & Puranik, R. (2011). Exercise Capacity and Stroke Volume are Preserved Even with Severely Dilated Right Ventricle, Late After Tetralogy Repair. Heart, Lung and Circulation, 20, S235–S236. https://doi.org/10.1016/j.hlc.2011.05.579