Three-dimensional echocardiography and myocardial imaging echocardiography in the evaluation of arrhythmogenic right ventricular dysplasia

Purpose. Arrhythmogenic right ventricular dysplasia (ARVD) is a heritable cardiomyopathy characterized by the fibrofatty replacement of right ventricular (RV) myocardium leading to RV failure and arrhythmias in young athletes. In this study we sought to evaluate the potential utility of three-dimensional echocardiography (3DE), tissue Doppler imaging (TDI) and speckle tracking imaging (STI) to quantitate RV function and their potential role in diagnosing ARVD. Methods. We studied 13 patients with ARVD (diagnosed by task force criteria) and 13 healthy age- and sex-matched subjects. RV internal diameters, outflow tract diameter, fractional area change and tricuspid annular systolic excursion were determined by transthoracic echocardiography. 3DE was performed as a full-volume scan of the LV and RV from the apical position using a system equipped with a real-time X3 transducer (Vivid 9 ultrasound system, GE, Horten, Norway). RV and LV annular peak systolic velocities (S) were measured by TDI. RV and LV peak systolic strain (), peak systolic strain rate (SR-S), and early (SR-E) and late (SR-A) diastolic strain rate were obtained in the basal, mid and apical segments in apical 4-chamber view both by TDI and STI. Averaged LV rotation and rotational velocities from the base and apex were also obtained by STI and used for calculation of LV torsion. All measurements were taken from an acceptable tracing and determined using offline analysis programs (EchoPAC, version 9.0, GE Ultrasound). Results. Patients with ARVD had a decreased RV ejection fraction (3D-RVEF) compared to controls (0.46± 0.11 vs 0.55±0.06, p<.01). STI- (all segments pooled: -9.7±3.0% vs -27±3.2%, p<.001), TDI- (-10.1±3.6% vs -28±4.4%, p<.001), STI-SR-S (-0.89±0.39 vs -1.66±0.89 s-1, p<.005), TDI-SR-S (-1.09±0.38 vs -1.82±0.93 s-1, p<.005), STI-SR-E (1.58±0.47 vs 2.27±0.88 s-1, p<.005), and TDI-SR-E (1.67±0.68 vs 2.42±1.03 s-1, p<.005) were significantly lower in patients with ARVD compared with controls, even in the subset of patients with apparently normal RV by conventional echocardiography. In 3/13 patients LV strain and torsion were significantly lower compared with controls (p<.005). ROC curves suggested that the thresholds offering an adequate compromise between sensitivity and specificity for detection of ARVD were 42% for 3D-RVEF (AUC 0.89), -22% for RV STI- (AUC 0.87), -26% for RV TDI- (AUC 0.79), -7.2 cm/sec for RV TDI-S velocity (AUC 0.75), -0.63 sec-1 for RV STI-SR-S (AUC 0.74), and -0.71 sec-1 for RV TDI-SR-S (AUC 0.72). Conclusions. Our data show that 3DE, TDI and STI have potential clinical value in the management of patients with suspected ARVD and may enable quantitative assessment of RV function and detection of ARVD.