Right ventricular global longitudinal strain in repaired tetralogy of Fallot.

BACKGROUND: Echocardiogram has limitations in effectively assessing right ventricular (RV) function in children post tetralogy of Fallot (TOF) repair. We evaluated the utility of speckle tracking echocardiography (STE)-based RV global longitudinal strain (GLS) for the assessment of RV systolic function.

METHODS: All patients with repaired TOF who had both echocardiograms and cardiac MRI (CMR) within a 6-month interval were included. RV volumes and ejection fraction (EF) were obtained by CMRs. Traditional echocardiographic function parameters and RV GLS were compared to CMR-derived RV EF. Subjects were divided into two groups based on CMR RV EF (group I: RV EF ≥45%; and group II: RV EF <45%).

RESULTS: A total of 57 subjects were included. Mean age was 13.0±3.6 years and 58% were males. Group I had 39 subjects and group II had 18. Only six of the 18 patients (33%) in group II were identified as having at least mild RV dysfunction by echocardiogram. The mean RV GLS was significantly abnormal in group II (-15.3±3.8%) compared to group I (-20.9±3.3%; P<.001). By ROC analysis, an RV GLS cutoff value of -18% had 78% sensitivity and 77% specificity in identifying RV EF <45% (area under curve .87, P<.001). Intra- and inter-observer reproducibility of RV GLS were good.

CONCLUSION: RV GLS is a simple and effective tool for the assessment of RV systolic function in patients post TOF repair. This technique would help further refine patient selection for timing of CMR and management.