For a long time, the diagnosis of an acute myocardial infarction (AMI) seen in outdoor patients, was only relying on ECG findings. For that reason a certain amount of patients suffering from an AMI showing an atypical or not contributive ECG had not been identified as such and in consequence did not benefit from any prehospital treatment or had not been admitted in coronary care unit (CCU). With the arrival of the biological bed side monitoring in the SAMU, it became possible to measure via TRIAGE Cardiac the biological parameters of an AMI (myoglobin, troponin Ic and CKMB) and so confirm or exclude the diagnosis in certain cases. Other markers became measurable, such as BNP (brain natriuretic protein) a marker for early detection of heart failure. This natriuretic peptide is used during hospitalisation as a prognostic value in acute coronary syndrome with no cardiac insufficiency associated. More recently a semi quantitative test CardioDetect using the early release of h-FABP (heart fatty acid binding) showed a better sensibility in the first hours after chest-pain onset in out-door patients. The experience of the use of these biological bed side tests in the prehospital phase is only recent, but already permits a better management of out door patients. The future of there employ is promising. The combined use of these different markers in out door patients will probably allow in the near future identifying high risk patients.