[In and out-of-hospital cardiac arrest and echography: a review].

Cardiac arrest is a frequent emergency for doctors and resuscitation teams. Patients displaying asystole or pulseless electrical activity are non-shockable. They have extremely poor outcomes. The use of sonographers might contribute to a better understanding of cardiac arrest (CA) etiology and facilitate its treatment. A systematic search in databases (NLM-Gateway, CNRS-INIST/Pascal, Science Direct, Ovid, and Bibliovie) of primary documents and notices allowed us to select clinical trial studies. Editorials, case report and animals studies were excluded from the analysis. The various physiopathological and semiological status revealed by echocardiography are useful to detect the aetiology of cardiac arrest. In the very first minutes following the arrest, a significant increase of right ventricle (RV) volume suggests a pulmonary thromboembolism or a RV infarction. After 4 min of CA, a physiological increase of RV volume is observed, in relation with the pressure balance between high and low arteriovenous pressures. RV and/or left ventricle collapses are straightaway pathological whichever due to pericardic effusion, pneumothorax or shock. A synthesis algorithm dedicated to care of CA, including transthoracic echocardiography for search of curable causes, is proposed. This algorithm fulfills the ILCOR, ERC and AHA recommendations. The echocardiography should be part of ACLS, nevertheless clinical studies are needed to assess its impact on morbimortality.