Tricuspid valve magnetic resonance imaging phase contrast velocity-encoded flow quantification for follow up of tetralogy of Fallot

Our purpose was to identify E- and A-wave flow patterns across the tricuspid valve in tetralogy of Fallot (TOF) patients following repair using magnetic resonance imaging phase contrast velocity-encoded flow quantification and to correlate them with measurements of right ventricle enlargement. The study included 33 children following TOF repair who had MRI examinations that included cine imaging to quantify ventricle size and function and flow analysis across the atria-ventricular valves to evaluate ventricle in-flow patterns. The E:A ratio was calculated for each patient and the population separated into alpha (E:A ratio >= 1.4) and beta (E:A ratio < 1.4) groups. Significant association was present between the beta group and right ventricle end diastolic volume index >= 140 ml/m(2) (P = 0.046), right ventricle end systolic volume index >= 70 ml/m(2) (P = 0.02), and end diastolic volume right ventricle to left ventricle >= 2.0 (P = 0.003). A reduction in the E:A wave ratio across the tricuspid valve is associated with right ventricle diastolic dysfunction and correlated well in our study with right ventricle enlargement. This may be a useful criterion for determining the timing of valved pulmonary conduit surgery in children following TOF repair.