CPR, the acronym for Cardiopulmonary Resuscitation, is one of the most common rescue techniques taught in the United States. The American Heart Association trains more than 12 million people annually in CPR. If you've ever taken a CPR class, you were probably taught to give a steady cycle of air and chest compressions. But new research suggests focusing on chest compressions only is more likely to save lives. That could lead to a shift in the way we learn CPR.