 Rationale: Sudden cardiac death, mainly caused by ventricular arrhythmias VA, is a major cause of morbidity and mortality in non-ischemic cardiomyopathy NICM. Therapies that effectively prevent VA are lacking. Improved understanding of the substrate and mechanisms of VA in NICM may allow more effective, individualized and substrate-based therapies to be developed. In addition, risk stratification in NICM needs to be improved so that therapies can be allocated more efficiently. 