Effect of real-time CPR feedback reported at resuscitation science symposium Emergency medical service (EMS) providers in the United States assess an estimated 350,000 cardiac arrests each year. Only 5 to 10 percent of people who have sudden cardiac arrest survive. Better quality cardiopulmonary resuscitation (CPR) provided by prehospital EMS providers may be associated with better patient outcome. view more (2009-11-23)