Longitudinal Strain and Sudden Cardiac Death

Several cardiac conditions are associated with the risk of ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Identification of the individuals at increased risk of these events is essential to facilitate the appropriate measures to prevent SCD. Several clinical, electrocardiographic, and imaging markers have been used for this purpose with varying accuracy. Recently, longitudinal myocardial strain assessed using speckle-tracking echocardiography has been shown to have incremental value in the prediction of SCD risk. Strain imaging allows quantification of the abnormalities in the magnitude and timing of the segmental myocardial contraction, which is a surrogate for underlying myocardial fibrosis and myofiber disarray. Reduced segmental strain and temporal heterogeneity indicate electromechanical dispersion, which is the primary substrate for VAs and SCD. This review summarizes current evidence regarding the utility of longitudinal strain for the prediction of SCD risk.