The current understanding recognizes dilated cardiomyopathy as a condition defined by cardiac enlargement that manifests clinically with symptoms of congestive heart failure. However, sudden cardiac death (SCD) can be the first clinical manifestation of the disease as well, although the main cause of death remains advanced heart failure. In patients with dilated cardiomyopathy, implantation of an implantable cardioverter defibrillator (ICD) reduced the mortality rate by approximately 30%, indicating that ventricular tachycardia and ventricular fibrillation are important causes of death. However, severe bradycardia or pulseless electrical activity can contribute as a cause of SCD as well. Since ICDs are highly efficacious in the prevention of SCD, identifying patients at highest risk of SCD is crucial for saving life, reducing associated complications, and reducing the burden of costs. However, registry data showed that the majority of sudden deaths occur in patients who do not fulfil the criteria for primary prevention with an ICD.
