Progression of right ventricular dilation in repaired tetralogy of Fallot

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.

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).

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).

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.