cardiac arrest, resuscitation; cardiac massage, open-chest; CPR, open-chest cardiac massage; resuscitation, from cardiac arrest Improved Resuscitation from Cardiac Arrest with Open-Chest Massage A study was done to assess the effect of open-chest massage on resuscitation from cardiac arrest. Ten mongrel dogs weighing 20.3 ++. 3.2 kg were fibrillated electrically. Cardiopulmonary resuscitation (CPR) was initiated and continued for 15 minutes. Half the dogs with coronary perfusion pressures less than 30 mm Hg underwent thoracotomy and internal cardiac massage for three minutes. Closed-chest massage was continued with the other dogs. All dogs were defibrillated at 19 minutes, and resuscitation was determined at 20 minutes after defibrillation. None of the dogs in the closed-chest massage group was resuscitated successfully. Four of the five dogs that underwent open cardiac massage were resuscitated. Significant differences in aortic pressures and coronary perfusion pressures were noted for the first two minutes of open-chest massage (P < .05). The results of this study indicate that resuscitation may be improved using open-chest massage when closedchest massage fails to produce an adequate coronary perfusion pressure.