Perspective:

This impressive study of two large cohorts is the first to look at RV deformation patterns and RV mechanical dispersion in both patients with AC and their mutation-positive family members. Current risk stratification tools have not included regional and subtle RV function on echocardiography, but instead relied on the global RV function and RV ejection by CMR. This study found that both abnormal deformation patterns and prolonged RV mechanical dispersion were independently associated with VA in these patients. Notably, the additive value of the two parameters increased the association with VA even more. The association between RV deformation patterns and mechanical dispersion and VA was equal to the association between CMR imaging and VA. However, there are many practical advantages to echocardiography over CMR, including cost and relative ease with which studies can be obtained and repeated over time. With the rapid expanse of cascade genetic testing, there will be a significant increase in mutation detection, often in asymptomatic genotype-positive family members who still have an important risk of ventricular arrhythmia. Use of this relatively straightforward echocardiographic deformation imaging may very well prove to be of great use for risk stratification in early disease, given its high sensitivity for ruling out life-threatening arrhythmias. Study limitations included its cross-sectional design with retrospective outcome adjudication, and to truly assess a predictive value, a prospective trial needs to be done. Simultaneously, a prospective trial would have to establish the frequency with which screening should be done.