Although the term Cardio-Pulmonary-Resuscitation or CPR was invented in 1960, people have been doing chest compressions for over 120 years. This article explains the importance of uninterrupted high quality chest compressions:

http://my.americanheart.org/professional/ScienceNews/Wake-up-CPR-providers-High-quality-CPR-is-wanted-and-needed_UCM_452907_Article.jsp