Progression of right ventricular dilation in repaired tetralogy of Fallot

Purpose: To evaluate factors associated with rapid rate of progression (ROP) of right ventricular (RV) dilation by cardiac MRI in repaired tetralogy of Fallot (TOF) patients.

Materials and methods: All patients with repaired TOF with two MRIs were included. RV volumes and function were assessed by MRIs performed on a GE 1.5 Tesla (T) platform. The ROP of RV dilation was calculated as the difference between the last and first RV indexed end-diastolic volumes (iEDV) divided by the time difference. Subjects were divided into two groups: Group I-rapid ROP (top quartile of ROP) and Group II-slower ROP (lower three quartiles).

Results: A total of 61 subjects were included. Mean age was 18.0 ± 9.7 years and duration between MRIs 3.4 ± 2.1 years. Median ROP for RV iEDV was 2.0 (-12.7 to 27.8) mL/m(2) /year. Fifteen subjects were in Group I and 46 in Group II. RV iEDV, RV ejection fraction, RV indexed end-systolic volume (iESV) were significantly different between groups. By multivariable analysis, RV iESV was the only independent parameter associated with rapid RV dilation (P < 0.01).

Conclusion: There was no significant change in RV iEDV in majority of repaired TOF subjects. RV iESV was the best parameter associated with more rapid RV dilation.