• Composite criteria includes during the first 48 hours : death, tracheal intubation and mechanical ventilation rates, persistence of inclusion criteria for respiratory distress and shock until H2, reappearance of inclusion criteria after H2. [ Time Frame: 48 hours ] [ Designated as safety issue: Yes ]
  

• brain natriuretic factor value curves from H0, H6 and H24; composite criteria without intubation rate; clinical and biological parameters evolution during the first 48 hours, myocardial infarction rate, CPAP non tol [ Time Frame: H0, H6, H24, H48 ] [ Designated as safety issue: Yes ]
  

Patients are included at home after informed consent by the emergency medical team and transported during the following 2 hours to a cardiac intensive care unit were the treatment is purchased as well. Randomization process has been done previously with envelopes ; group A : pharmaceutical treatment alone , B pharmaceutical plus CPAP. Medical treatment includes furosemide and nitroglycerin (continuous perfusion and bolus), inotropes if needed, and all other specific treatment required (ex : anti antiarrhythmic drugs). Doses are free, adapted to the clinical response for respiratory and hemodynamic distress. CPAP is a passive high flow venturi system device alimented by a hyperbaric oxygen. FiO2 can be controlled and adapted to the pulsed oxygen saturation. PEP must be initially celled at least at 7.5 cmH2O and increased to 10 if well tolerated.