['The aim of this study was to determine the accuracy of new quantitative echocardiographic strain and strain-rate imaging parameters to identify abnormal regional right ventricular (RV) deformation associated with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C).', 'A total of 34 patients with ARVD/C (confirmed by Task Force criteria) and 34 healthy controls were prospectively enrolled. Conventional echocardiography, including Doppler tissue imaging (DTI), was performed. Doppler and two-dimensional strain-derived velocity, strain, and strain rate were calculated in the apical, mid, and basal segments of the RV free wall.', 'RV dimensions were significantly increased in patients with ARVD/C (RV outflow tract 19.3+/-5.2 mm/m2 vs 14.1+/-2.2 mm/m2, P<.001; RV inflow tract 23.4+/-4.8 mm/m2 vs 18.8+/-2.4 mm/m2, P<.001), whereas left ventricular dimensions were not significantly different compared with controls. Strain and strain rate values were significantly lower in patients with ARVD/C in all 3 segments. All deformation parameters showed a higher accuracy to detect functional abnormalities compared with conventional echocardiographic criteria of dimensions or global systolic function. The lowest DTI strain value in any of the 3 analyzed segments showed the best receiver operating characteristics (area under the curve 0.97) with an optimal cutoff value of -18.2%.'] Does echocardiographic tissue deformation imaging quantify abnormal regional right ventricular function in arrhythmogenic right ventricular dysplasia/cardiomyopathy?