Reducing the intervals between giving cardiopulmonary resuscitation (CPR) and an electronic defibrillator shock after a person experiences cardiac arrest significantly improves survival, according to emergency medicine doctors at the University of Texas Southwestern Medical Center in Dallas.

In an international study, chest compressions applied within 10 seconds before the defibrillator shocks and within 20 seconds after the shock boosted survival chances by more than half compared to the rates for people who received chest compressions more than 20 seconds before or 40 seconds after the shock.

"We've been doing training in Dallas for two to three years to reduce the pauses between chest compressions and shocks to less than five seconds, and that has improved survival in the city about 60 percent," said Dr. Ahamed Idris, Professor of Emergency Medicine and Internal medicine at the university and a study co-author.

"This is really a very simple thing anyone can do to increase survivai," noted Dr. Idris, Director of the Dallas-Fort Worth Center for Resuscitation Research.

American Heart Association resuscitation guidelines advise minimizing interruptions to chest compression to 10 seconds or less. Previous studies, however, had not measured how such pauses in CPR affected survival through discharge from the hospital.

(Source: Circulation: Journal of the American Heart Association; July 2011.)