Range of ventricular dimensions and function by steady-state free precession cine MRI in repaired tetralogy of Fallot: right ventricular outflow tract patch vs. conduit repair.

PURPOSE: To characterize the range of biventricular size and function evaluated by steady-state free precession (SSFP) cine magnetic resonance (MR) in a large cohort of patients with repaired tetralogy of Fallot (TOF), and to compare these measurements in those with a right ventricular outflow tract (RVOT) patch vs. a right ventricle-to-pulmonary artery (RV-PA) conduit.

MATERIALS AND

METHODS

Analysis of ventricular size and function in 300 consecutive examinations in patients with repaired TOF evaluated by SSFP cine MR.

RESULTS

Of the 300 examinations performed in 256 patients, 69% had undergone repair with a RVOT patch and 31% with a RV-PA conduit. Compared to patients with RV-PA conduit, those with a RVOT patch had significantly more pulmonary regurgitation (PR) (38 +/- 17 vs. 23 +/- 16%, P < 0.0001), larger indexed RV end-diastolic volume (154 +/- 53 vs. 133 +/- 51 mL/m(2), P = 0.002), similar indexed end-systolic volume (80 +/- 39 vs. 74 +/- 46 mL/m(2), P = 0.31), higher ejection fraction (EF) (50 +/- 9 vs. 47 +/- 12%, P = 0.037), and lower mass-to-volume ratio (0.29 +/- 0.08 vs. 0.36 +/- 0.13, P < 0.0001). Pulmonary regurgitation fraction correlated positively with RV end-diastolic volume index in the RVOT patch group (r = 0.51, P < 0.0001) but not in the RV-PA conduit.

CONCLUSION

This study provides the range and distribution of biventricular size and function, and PR measured by MRI in a large contemporary cohort of patients with repaired TOF, and demonstrates important variations in RV mechanics between patients repaired with a RVOT patch and those with an RV-PA conduit.