Evolution of right ventricular size over time after tetralogy of Fallot repair: a longitudinal cardiac magnetic resonance study

Aims: It is commonly believed that pulmonary regurgitation (PR) after surgical repair of tetralogy of Fallot (TOF) leads to progressive right ventricular (RV) enlargement. However, progressive RV dilatation has never clearly been documented in this patient population. Therefore, we studied the size of the RV over time in patients after surgical TOF repair. Methods and results: Fifty-one consecutive patients after surgical TOF repair underwent at least two cardiovascular magnetic resonance (CMR) exams using a single CMR scanner. Patients with RV outflow tract obstruction, interventions other than the initial repair and CMR exams with use of sedation were excluded. Three subgroups with different repair techniques were studied: transannular patch repair [n = 22, age 17 +/- 10 years], subvalvular patch repair [n = 15, age 22 +/- 8 years], or non-patch repair/infundibulectomy (n = 14, age 28 +/- 11 years). Right ventricular end-diastolic volume index (RVEDVI) and PR fraction did not change during the 37 +/- 21 months follow-up between first and last CMR in the whole group (RVEDVI: 118 +/- 23 mL/m2 vs. 119 +/- 23 mL/m(2), P = 0.720; PR fraction: 33% (23-40%) vs. 32% (24-39%), P = 0.268). RVEDVI remained stable in all subgroups (transannular patch: 120 +/- 21 mL/m2 vs. 122 +/- 22 mL/m2, subvalvular patch: 112 +/- 23 mL/m(2) vs. 111 +/- 23 mL/m(2), non-patch: 123 +/- 28 mL/m2 vs. 123 +/- 23 mL/m(2), P = 0.827). RVEDVI at last CMR did not differ between groups (P = 0.301). Conclusions: This study shows no progression of RV dilatation in patients after surgical repair of TOF with moderately dilated RVs and significant PR during a 3-year follow-up. RV dilatation in our patient group seems to be independent from surgical repair techniques.