The optimal timing for magnetic resonance imaging in long-term follow-up of patients after a complete correction of the Tetralogy of Fallot

Objectives: Long-term pulmonary regurgitation (PR) leads to right ventricular (RV) dilatation and dysfunction. In patients after a complete correction of the tetralogy of Fallot (TOF) it represents the most frequent and high risk late complication. Magnetic resonance imaging (MRI) is an objective possibility for RV measurements; on the other hand MRI is complicated and not always accessible method. Background: We analyzed echocardiography (ECHO) and MRI parameters regarding RV dilatation and function and the correlation between these two methods with the aim to define optimal ECHO parameters indicating a necessity for further investigations. Patients and methods: In 50 patients with TOF > 10 years, after a complete surgical correction, ECHO and MRI were performed. Results: ECHO finding of end-diastolic diameter (EDD) of RV > 30mm was detected in 13 patients (26%) and in 30 patients (60 %) RV EDD above 4 standard deviations (SD) their normal values was present. MRI finding of end-diastolic volume (EDV) > 160 ml/m(2) was present in 14 patients (28 %) and end-systolic volume (ESV) > 85 ml/m(2) in 17 patients (34 %). Significant correlations between ECHO and MRI RV diastolic measurements were found (p=0.0001, r=0.34, resp. p=0.001, r=0.39). PR was significantly affecting diastolic RV dilatation (p=0.0001), on the other hand. RV dysfunction resulted in systolic RV dilatation (p=0.007). PR did not correlate with RV function (p=0.56). Conclusions: MRI is a golden standard for exact RV measurements and for the indication of pulmonary valve replacement, but ECHO still can be used during long-term follow-up, defining the point for further and more exact RV measurements (Tab. 2, Fig. 11, Ref. 17). Full Text in free PDF www.bmj.sk.