Morphine In Acute Myocardial Infarction

Inclusion Criteria: 1. Acute Myocardial Infarction less than 6 hours defined by 1. prolonged chest pain (\>15 min) 2. in association with * ST elevation 1mm or more in two contiguous leads * or occurence of Q wave in three contiguous leads * or occurence of left bundle branch block 2. Culprit lesion eligible for percutaneous coronary intervention (PCI) 3. TIMI flow 0 before PCI Exclusion Criteria: 1. Fibrinolysis 2. Allergy to morphine 3. Active epilepsy 4. Brain injury or intracranial hypertension 5. Previous AMI, coronary artery bypass graft (CABG) 6. Cardiac arrest 7. Cardiogenic shock, significant mitral regurgitation or intraventricular communication at inclusion 8. Mechanical ventilation at inclusion 9. Significant ventricular arrhythmia or atrioventricular block type II or III at inclusion 10. Decompensated chronic obstructive pulmonary disease at inclusion 11. chronic hepatocellular failure 12. MRI contraindications 13. Gadolinium chelates injection contraindications 14. Current treatment with morphine chlorhydrate, buprenorphine, nalbuphine, pentazocine