We propose a comparative case-control study on the 2 following groups of patients:

• Cases: 500 patients with ventricular fibrillation at the acute phase of myocardial infarct,
• Controls: 500 patients without ventricular fibrillation at the acute phase of myocardial infarct.

The primary endpoint in this study is the correlation phenotype/genotype of sudden death at the acute phase of myocardial infarct.

The first phase of the study, including patients' recruitment, clinical and biological data collection, will last 82 months. The second phase will concern the genotype/phenotype analysis and the identification of polymorphisms associated with a sudden death risk after a myocardial infarction.

This study will allow a better knowledge of the mechanisms of sudden death and the identification of new risk markers.

The number of sudden death is estimated around 50000 in France. In most cases, these deaths are due to myocardial infarction. This complication occurs, for 70% of cases, at the patient's residence, within 30 minutes following the thoracic pain. Emergency care often comes too late and allows only 2% of the patients having a heart failure to be revitalized.

At equal sex, age and clinical status, patients may or not develop ventricular rhythm disorders. Then, the notions of risk background and genetic disposition should be investigated.

No prospective study has been conducted on a sufficient number of patients yet. Such a study and the recent development of new genetic technologies will help identifying markers of sudden death risk at the acute phase of myocardial infarction.

The study we are implementing will increase knowledge on sudden death mechanisms at the acute phase of myocardial infarction. The analysis of phenotypic/genotypic relations will lead to an identification of new risk markers. Further evaluations of new diagnostic and therapeutic strategies will be possible on the basis of this trial.

Ventricular fibrillation at the acute phase of myocardial infarction follows a polygenic determinism. The genes involved in this electrical trouble are those which lead to the expression of potassic, calcic and sodic channels of ventricular myocytes: KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2, KCNJ2, PRKAG2, RyR2, PKP2, DSP, CASQ2, CACNA1C, and FKBP1B.

An association of a favourable genetic background and ischemia represents a cause for ventricular arrhythmia as a complication of myocardial infarction.

Haplotypes or genes considered as new markers for sudden death risk of ischemic origin will be searched.

Inclusion Criteria:

• All patients admitted to ICU for MI and presenting the following criteria:
• Age > 18
• Group 1 (Case) Patients with cardiac arrest and ventricular fibrillation developed up to 24 h post MI Group 2 (control) Patients with MI (no ventricular fibrillation)
• Written informed consent.

Exclusion Criteria:

• No written informed consent
• Known Medical History of cardiomyopathy, including acute coronary syndrome

Cases: 500 patients with ventricular fibrillation at the acute phase of myocardial infarct, Controls: 500 patients without ventricular fibrillation at the acute phase of myocardial infarct.