CHICAGO – People who suffer cardiac arrest outside a hospital are three times more likely to survive if they receive a rapid electric shock, says a study appearing Wednesday in a leading US medical journal. 

   Using a defibrillator on victims within eight minutes of a heart attack increases survival rates by 33 percent, says the study, to be published by the Journal of the American Medical Association (JAMA).

   An experiment by Ottawa Hospital researchers in Canada showed that 5.2 percent of out-of-hospital patients survived cardiac arrest when they received a rapid electric shock, compared to a 3.9 percent survival rate for those who did not receive defibrillation.

   The study’s main author, Ian Stiell, reported that almost 80 percent of the 66 patients who lived at least a year after being resuscitated with electric shock had "very good" cerebral and physical functions.

   A separate article appearing in the same issue says that administering cardio-pulmonary resuscitation (CPR) for 90 seconds prior to defibrillation increases survival chances some 24-30 percent.

   And the number of survivors with good neurological function upon leaving the hospital increased from 71 to 79 percent when they received both treatments, says Leonard Cobb of Harborview Medical Center in Seattle, Washington.