The aim of this project is to identify common genetic polymorphisms associated with the occurrence of rhythmic events in patients with severe cardiomyopathy.

Inclusion Criteria:

• Patients implanted for primary prevention, an implantable cardioverter defibrillator (ICD) single or double room, for severe cardiomyopathy (EF <35%)
• Patients with ischemic cardiomyopathy or idiopathic dilated cardiomyopathy.- "Appropriate treatment" group: patients who had a rhythmic event (before or after inclusion) appropriately treated either by administering an electric shock or by antiarrhythmic stimulation
• Group "no event" patients who have never received treatment or electrical antiarrhythmic stimulation and with a minimum follow-up of three years before inclusion and did not receive proper treatment during the follow up period of the study

Exclusion Criteria:

• Patients implanted with an ICD for primary prevention in the context of a family hereditary disease (long QT syndrome, Brugada syndrome, hypertrophic cardiomyopathy, ventricular tachycardia catecholergic right ventricular dysplasia ...).
• Patients with left ventricular function greater than 35%.
• Patients implanted with a defibrillator function resynchronization.
• Patients minors, adults under guardianship and protected persons are eligible under this project.

Genetic analysis will compare 500 patients implanted with an ICD for primary prevention and having received an appropriate shock and another 500 patients implanted with an ICD for primary prevention and have not received appropriate shock after a minimum follow-up three years before inclusion. To allow the matching of two groups, it requires to recruit 500 patients in the "appropriate treatment" group and 1000 patients in the "no event" group.