Extracorporeal cardiac mechanical stimulation: precordial thump and precordial percussion.

INTRODUCTION: External cardiac mechanical stimulation is one of the fastest resuscitative manoeuvres possible in the emergency setting. Precordial thump (PT), initially reported for treatment of atrio-ventricular block, has been subsequently described to cardiovert also ventricular tachycardia (VT) and fibrillation (VF). PT efficacy, mechanics and mechanisms remain poorly characterized. SOURCES OF DATA: Appropriate MESH and free terms were searched on PubMed, Embase and the Cochrane Library. Cross-referencing from articles and reviews, and forward search using SCOPUS and Google scholar have also been performed. Pre-set inclusion and exclusion criteria were applied to retrieved references on PT, which were then reviewed, summarized and interpreted. AREAS OF AGREEMENT: PT is not effective in treating VF, and of limited use for VT, although it has a very good safety profile (97% no changed/improved rhythm). If delivered, PT should be applied as early as possible after cardiac arrest, and cardio-pulmonary resuscitation (CPR) should begin with no delay if not effective. AREAS OF CONTROVERSY: A relatively large fraction of reported positive outcomes (both for PT and the less forceful but serially applied precordial percussion) in witnessed asystole should be considered when critically reviewing present CPR recommendations. In addition, mechanisms, energy requirements and timing are analysed and discussed. GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH: The 2005 ALS guidelines recommend PT delivery only by healthcare professionals trained in the technique. The use of training aids should therefore be explored, regardless of whether they are based on stand-alone devices or integrated within resuscitation mannequins.