Higher extracellular volume is associated with longer bypass times at corrective surgery and reduced exercise tolerance in children late after repair of tetralogy of Fallot

Results There was no difference in ECV between 31 TOF patients (23.6 ± 3.3, age at CMR 13.9 ± 2.4 years, 19 male) and 15 controls (23.4 ± 3.0, age at CMR 13.4 ± 2.6 years, 7 male). ECV correlated with z-scores of LV end-diastolic volumes and of right ventricular (RV) enddiastolic and end-systolic volumes (r = 0.39, p < 0.05; r = 0.46, p < 0.01; and r = 0.43, p < 0.05, respectively). LV ECV did not correlate with with LV or RV ejection fraction, indexed right and left ventricular enddiastolic volumes or pulmonary regurgitation fraction or regurgitant volumes. Female TOF patients had higher ECVs as compared to males (25.7 ± 1.8% versus 22.9 ± 3.1%, p < 0.005). There were no gender differences in controls. Bypass-time during complete repair correlated with LV ECV (r = 0.46, p < 0.05). Patients who had undergone either a valve sparing repair or received a valved right ventricle to pulmonary artery conduit had a lower ECV than those after transannular patch repair (22.8 ± 2.7% versus 26.0 ± 3.0%, p < 0.05).Maximum workload on exercise testing, as a percent of predicted based on reference populations, correlated inversely with ECV (r = -0.62, p < 0.05). There were no correlations between ECV and myocardial strain, strain rate or torsion.