Cardiac arrest patients who get cardiopulmonary resuscitation (CPR) from a bystander at the scene may have better survival odds even when an ambulance takes a long time to arrive, a Danish study suggests. 
Researchers examined data on 7,623 cardiac arrest patients and found when an ambulance arrived within five minutes of a 911 call, patients were 2.3 times more likely to survive at least 30 days if they received bystander CPR than if they didn't get this aid at the scene. 
"Early CPR saves lives, and the lack of CPR efforts from bystanders could result in significantly decreased chances of survival," said lead study author Dr. Shahzleen Rajan of Copenhagen University Hospital in Denmark. 
Cardiac arrest involves the abrupt loss of heart function, breathing and consciousness. Unlike a heart attack, which happens when blood flow to a portion of the heart is blocked, cardiac arrest occurs when the heart's electrical system malfunctions, often due to irregular heart rhythms. Cardiac arrest may occur with no warning and is often fatal. 
Chest compressions or CPR can help restore circulation, increasing the odds of survival. Bystander CPR generally won't restore a normal heart rhythm but it can buy time by maintaining blood flow to vital organs. 
"We know from previous research that 1 in 8 people survive after a cardiac arrest if a bystander initiates CPR before the arrival of the emergency medical services," Rajan said. "In contrast, if CPR is not initiated before the arrival of the emergency medical services, only 1 in 30 people survive a cardiac arrest".

Source: QNA