Background In a departure from the previous strategy of immediate defibrillation, the 2005
resuscitation guidelines from the American Heart Association–International Liaison
Committee on Resuscitation suggested that emergency medical service (EMS) personnel
could provide 2 minutes of cardiopulmonary resuscitation (CPR) before the first analysis of
cardiac rhythm. We compared the strategy of a brief period of CPR with early analysis of
rhythm with the strategy of a longer period of CPR with delayed analysis of rhythm. Methods …

This study compared the strategy of a brief period of cardiopulmonary resuscitation (CPR)
with early analysis of rhythm and delivery of indicated defibrillatory shocks as soon as
possible with the strategy of a longer period of CPR with a delayed analysis of rhythm. The
study was a cluster-randomized trial comprising 10 United States and Canadian universities
and their regional emergency medical service (EMS) systems. Most patients were enrolled
simultaneously in the study described herein as well as a concurrent study comparing the …