Obesity leads to underestimation of ventricular volumes and abnormal myocardial strain in repaired Tetralogy of Fallot as measured by cardiac MRI

Background Obesity is an increasing epidemic that has not spared children and adults with congenital heart disease. Patients with repaired tetralogy of Fallot with trans-annular patch (rTOF-TAP) have significant pulmonary insufficiency and right ventricular (RV) enlargement. Recommendations for pulmonary valve replacement (PVR) include body surface area (BSA)-indexed RV end diastolic volume (RVEDVi) >150 ml/m2 or indexed RV end systolic volume (RVESVi) >80 ml/m2, estimated by cardiac MRI (CMR). We hypothesized that: 1) overweight and obese patients with rTOF-TAP have underestimated indexed ventricular volumes when compared to volumes indexed to ideal BSA and 2) these patients have altered parameters of cardiac function compared to weight appropriate patients.