Get a cholesterol test.

The newest guidelines call for having a fasting lipoprotein profile every five years starting when you're 20. The blood test measures total cholesterol—which should be less than 200 mg/dl (milligrams per deciliter)—and its Dr. Jekyll/Mr. Hyde components: good HDL, which protects your ticker, and demon LDL, a major cause of heart disease ("Happy" and "Lousy" are how one doctor teaches patients to remember which is which). To lower cholesterol, doctors usually recommend dietary changes (note that only foods with soluble fiber, like oats and beans, have been shown to help lower cholesterol; whole-wheat bread and bran muffins with insoluble fiber have not). There are also effective medications.

 
Eat, drink, and be wary.

The American Heart Association (AHA) recommends getting only 7 to 10 percent, or less, of your total daily calories from saturated fat—the delicious kind in beef and butter. If you're having separation anxiety over the thought of leaving your cheeseburgers and fries, here's a little cheer: Studies show that moderate drinking—wine, beer and spirits—lowers the risk of heart attack. Just keep it to one drink a day.

 
Get to know your blood pressure.

Ignorance could be lethal. Nearly a third of people with high blood pressure, also called hypertension, are unaware they have it—and they're six times more likely to have congestive heart failure (and seven times more likely to suffer a stroke) than someone who has gotten her high blood pressure under control. Losing weight and reducing salt in your diet—the AHA suggests a max of one and a quarter teaspoons (2,400 milligrams) per day—are the two most effective ways to lower blood pressure; medications also help.

 
Chuck the spare tire.

The heavier you are, the more likely you'll suffer from hypertension and high cholesterol. Unfortunately for "apple" types, carrying your weight around the middle (rather than being bottom-heavy, or a "pear") puts you at additional risk of heart disease. That's because the inner fat cushioning the abdominal organs is linked to lower levels of the good cholesterol and higher levels of the bad kind, according to Nieca Goldberg, M.D., chief of the women's heart program at Lenox Hill Hospital in New York City and author of Women Are Not Small Men: Life-Saving Strategies for Preventing and Healing Heart Disease in Women. To see if your figure puts you at risk, she says, divide your waist measurement by your hip measurement. If you get above 0.8, you need to lose weight.

 
Get a duck's back.

The link between stress and heart disease is still being investigated, but many experts believe you can boost your cardiovascular immunity by cultivating calm. Slowing down and learning to take things in stride (walking places versus running everywhere, bringing a book to the doctor's office instead of fuming over the wait) could save your heart. Try stress management courses, meditation and letting off steam with friends.

 
Make a move.

By doing absolutely nothing (physical, that is), you nearly double your odds of getting felled by a heart attack, according to the Mayo Clinic Heart Book. A little exercise goes a long way in keeping your heart muscle fit and in controlling weight, cholesterol, blood pressure and stress. "Just walking at a three-mph pace for 30 minutes most days of the week can reduce one's risk by one third," says Briller. "And there's some data that shows that three ten-minute sessions do just as well." (Call 800-242-8721 or visit www.americanheart.org to find out about the American Heart Walk program.)

 
Do whatever it takes to quit smoking.

Smokers are up to six times more likely to suffer a heart attack than nonsmokers, according to the National Heart, Lung and Blood Institute. And don't fool yourself with light brands, because low-tar and low-nicotine cigarettes do nothing to lessen the risk of heart disease. One more reason to clear the smoke: between 37,000 and 40,000 people die every year from cardiovascular disease caused by other folks lighting up.

 
Learn the signs of a heart attack.

Women often don't know when they're having a heart attack because the symptoms are different than they are in men. Signs to watch for: chest discomfort, lightheadedness, nausea, shortness of breath, breaking out in a cold sweat, overwhelming fatigue and pain in the arms, jaw, neck, back or stomach.