Echocardiographic Assessment of Adults with Repaired Tetralogy of Fallot: A Cardiovascular Magnetic Resonance Comparison Study

Background Surgical management of the tetralogy of Fallot (TOF) results in anatomic and functional abnormalities in the majority of patients. Right ventricular (RV) dilation from pulmonary regurgitation (PR), residual atrial and/or ventricular septal defect, tricuspid regurgitation, right ventricular outflow tract (RVOT) aneurysm, and pulmonary artery peripheral stenosis are some of the abnormalities frequently encountered in patients with repaired TOF. Cardiovascular magnetic resonance (CMR) can provide assessments of anatomical connections, biventricular function, flow measurement, and more, without ionizing radiation. Echocardiography is the most frequently used modality for the initial assessment and follow-up of most patients with CHD. We sought to evaluate adult patients with repaired TOF by transthoracic echocardiography and compare them with CMR. Methods 156 patients (52 women, mean age= 23 ± 5.5 years) late after TOF repair with severe PR were evaluated. Ventricular size and function and TOF -associated anomalies such as patent ductus arteriosus (PDA), peripheral pulmonary stenosis (PPS), and persistent left superior vena cava (LSVC) were evaluated by transthoracic echocardiography and CMR separately. Results Mean of LV ejection fraction by CMR was 52 ± 9 % and by echocardiography was 47 ± 5.1 %. We found a significant correlation between LVEF assessed by CMR and 2D visual assessment in multiple views. Mean of RVEF by CMR was 37± 8 % and RV end diastolic volume index was 161± 57.3 mm3. Linear correlation between CMR-RVEF and RVEF measured by echocardiography was weak. There was almost perfect agreement between CMR and echocardiography for the diagnosis of LSVC (99.2%). Agreement was 88.3% in the diagnosis of PDA, 66.4% in the diagnosis of PPS, and 93% in the diagnosis of the right aortic arch was. Conclusions Adults late after repaired TOF have significantly reduced biventricular systolic function. Despite abnormal LV geometry, visual assessment of LV systolic function by an expert echocardiologist has an acceptable agreement compared to the quantitative measurement of LV systolic function by CMR. However, the correlation between CMR-RVEF and RVEF measured by echocardiography is weak. We found incremental diagnostic value of CMR in PPS and PDA. Atrial septal defect and ventricular septal defect are found more frequently by echocardiography.