When 51-year-old James (Tony Soprano) Gandolfini suffered a heart attack while visiting Rome last summer, his chances for survival might have increased if it had happened on a movie set, where there's often a medical staff trained in cardiopulmonary resuscitation.

But unfortunately for millions of people around the globe and more than 360,000 North Americans every year who have "out-of-hospital cardiac arrests" or OHCA's, your average bystander isn't prepared to administer CPR, and the chances of pulling through an on-the-street heart attack are not great. In Detroit, OHCA's have a 0.2 percent survival rate. In Seattle (the U.S. gold standard), survival rates still hit only 16 percent.

What improves survival rates, according to a Danish study, is a public education push that teaches how and when to do CPR, along with smarter medical-response procedures. Danish efforts have elevated their OHCA survival rate to an impressive 44 percent.

For you to help improve OHCA survival rates in North America, here are CPR basics:

• First, call 911; then start chest compressions. No need to do mouth-to-mouth resuscitation. It turns out hands-only CPR is the most effective technique for saving lives in real-life OHCA situations.
• Place one flat hand over the center of the victim's chest and your other open hand on top of that. Press down hard (chest should depress 2 inches) for 100 beats a minute. If someone's available, have that person count with you.
• Stick with it until help arrives, and ask someone else to relieve you if you get worn out.