MODEL RELEASED. Chest compressions. First aider carrying out chest compressions on a patient. This is intended to restart a heart that has stopped, either from the shock of an accident or from a heart attack (myocardial infarction). It is used in the procedure known as CPR (cardio-pulmonary resuscitation) that also involves mouth-to-mouth resuscitation to breathe for the patient. The two procedures are alternated until a pulse returns and the patient is breathing unaided. Further emergency medical care and monitoring will then be required.