Right ventricular strain predicts functional capacity in patients with repaired tetralogy of Fallot

ABSTRACT

Echocardiography-derived strain rate and strain may provide new insights into right ventricular [RV] function in repaired tetralogy of Fallot [rTOF] patients in whom evaluation of RV function and functional capacity has an important role in further management. In 45 rTOF patients with severe pulmonary regurgitation. the routine echocardiography-derived indices for evaluation of RV function [TAPSE. RVOT Excursion and eyeball method] and longitudinal strain rate and strain were acquired from basal, mid and apical segments of RV free wall [RVFW] and interventricular septum; functional capacity was measured by standard Bruce protocol exercise testing. All patients had some degrees of RV dysfunction with no correlations between results of routine indices and functional capacity. Reduced RVFW average systolic strain was correlated directly with reduced functional capacity [r = 0.86[P <0.001], this was also true for peak systolic strain of basal and mid segments of RVFW. Derivation of ROC curves showed that a cut-off value of 15.8% for average RVFW systolic strain predicts good exercise capacity [>/= 10 METs] with a sensitivity of 91.2% and a specificity of 100%. Although routine echocardiography indices are not accurate tools in rTOF patients, systolic strain of RVFW seems to be reliable in estimation of RV function and functional capacity