Right ventricular systolic function and mechanical dispersion identify patients with arrhythmogenic right ventricular cardiomyopathy
To assess right ventricular (RV) regional and global systolic function using feature tracking (FT) in patients with a definite diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC) and to investigate if changes in strain amplitude and mechanical dispersion indicate a propensity for arrhythmia.Materials and Methods:
Twenty-seven patients fulfilling Task Force Criteria for ARVC and 24 healthy volunteers underwent MR at 1·5 Tesla. Steady-state free precession cine of long-axis slices and a short-axis stack of the RV was acquired. Segmental longitudinal systolic strain amplitude and time-to-peak (TTP) strain were measured in the four- and two-chamber views of the RV.Results:
Compared to controls, patients with ARVC had lower RV ejection fraction (RVEF), (53% vs 57%, P = 0·012) and lower longitudinal strain amplitude in the RV free wall (-20·6 vs -26·3%, P = 0·014) and in the basal part of the RV (-22·8 vs -31·7%, P<0·001). Mechanical dispersion, defined as the standard deviation (SD) of TTP of RV segments, was larger in patients with ARVC (48 ms [21–74] vs 35 ms [13–66 ms], P = 0·02). Patients with ventricular tachycardia (VT) or non-sustained VT had lower RVEF (46% vs 55%, P = 0·008), but did not have significantly lower RV strain amplitude (−19·5% vs 21·0%, P = 0·073) and no signs of mechanical dispersion (49 ms vs 48 ms, P = 0·861) compared to patients without arrhythmia.Conclusion:
ARVC patients had lower longitudinal absolute strain amplitude in basal RV segments and increased mechanical dispersion compared to healthy volunteers, but the presence of mechanical dispersion was not predictive of ventricular arrhythmia.