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.