MRI with late gadolinium enhancement as a predictor of ventricular arrhythmias

Despite considerable progress in reducing sudden cardiac death (SCD), mortality remains high and risk stratification algorithms are limited. Many approaches to identifying at-risk patients target the electrophysiologic triggers or modulators of ventricular arrhythmias. Other than global left ventricular function, there has been minimal emphasis on evaluating the anatomic substrate that supports arrhythmia circuits, namely myocardial scarring. Myocardial scarring and fibrosis occurs in both ischemic and nonischemic cardiomyopathies and is detected noninvasively by cardiac MRI with late gadolinium enhancement (CMR-LGE). There is growing literature relating CMR-LGE to arrhythmic surrogates and clinical outcomes in vulnerable cohorts. Additionally, knowledge of the presence and extent of CMR-LGE is potentially valuable for guiding catheter ablative therapies. The incremental value of CMR-LGE in predicting SCD, above current risk factors, remains unknown, but its unique ability to provide anatomic and tissue characterization contributes to its appeal as a promising noninvasive tool for identifying susceptible patients.