"It accounts for about 390,000 deaths in the United States each year," said physician Robert J. Myerburg.
At least 70% of all cardiac arrests occur outside hospitals and seem to come out of nowhere.
"50% of sudden cardiac deaths are first cardiac events, meaning the patient did not know they had heart disease," he said.
But nearly 45% of those who were saved out of the hospital were saved by someone who immediately started CPR. Swedish researchers say the 30-day survival rate after a cardiac arrest is under 7%.
There is also the risk of broken bones, a sore chest or lung collapse. A survey of 600 clinicians found that more than half said giving CPR, even if only 2% survive, is still appropriate.
Not all doctors or patients agree. So, if you're older than 65, discuss this with your family in advance. Generally, do not resuscitate orders apply only in the hospital.