Cardiac magnetic resonance imaging contributing to primary prevention and secondary prevention of sudden cardiac death: Contemporary usefulness and limitations.

Sudden cardiac death (SCD) is one of the most devastating sequelae of myocardial diseases and can be the initial symptom in younger athletes or middle-aged businesspeople. An implantable cardioverter defibrillator (ICD) prevents SCD and dramatically reduces the arrhythmic events in these patients; hence, the risk stratification for the SCD is important. In survivors of out-of-hospital cardiac arrest, identification of its etiologies is required to select the appropriate treatments following ICD installation. Cardiac magnetic resonance imaging (MRI) is useful for evaluating the morphology and function of the heart and for tissue characterization, MRI can therefore be used to stratify the risk of SCD associated with various myocardial diseases and leads to primary prevention using ICD. MRI can predict arrhythmic events, which suggest the progression of myocardial damage, following secondary prevention. In this review, we provide a clinical and MRI focused update and MRI protocol for the primary and secondary prevention of SCD. We summarize the contribution and limitations of cardiac MRI for prevention SCD using ICD implantation.