Right ventricular diastolic function in post-surgical Tetralogy of Fallot patients: A pilot study to make a comparison between echocardiography and cardiac MRI

Background: right ventricular (RV) systolic dysfunction is associated with poor outcomes in Tetralogy of Fallot (ToF) patients. Conversely, the influence of diastolic dysfunction in this setting is poorly known. In addition, evaluation of RV diastolic function by cardiac MRI is rarely performed. Materials and methods: twenty-four surgically treated ToF patients were enrolled in the study (54% males; median age at study: 28 (18–50) years; median age at surgery: 1.9 (0.4–8.2) years. They were studied by echocardiography to assess RV diastolic function in terms of traditional and TDI-derived parameters. At cardiac MRI, RV diastolic function was assessed by using phase-contrast analysis of flow through the tricuspid valve in short axis view. Diastolic dysfunction was graded as impaired relaxation, pseudo-normal, or restrictive physiology. Results: fifteen (62.5%) ToF subjects had echocardiographic evidence of diastolic dysfunction and eleven (45.8%) at cardiac MRI. Statistically significant correlation between echocardiographic and cardiac MRI parameters of diastolic dysfunction was weak (p < 0.05). The degree of RV diastolic dysfunction (expressed as E/E’ at TDI) was associated with right atrial volume indexed for body surface area at cardiac MRI (p < 0.0001). Greater number of interim palliative procedures was associated with higher E/E' (RV diastolic dysfunction) at echocardiography (p < 0.0003). Conclusions: diastolic dysfunction, as determined by echocardiography and cardiac MRI-derived measures, is prevalent in ToF. These measures are weakly associated with each other. Notwithstanding the limitations of this pilot study, the development of cardiac MRI parameters capable of correlating with RV relaxation is needed in ToF setting.