MATTERS OF THE HEART

The heart may be fickle, but the science of keeping it healthy can be even more so. Every year experts come up with new insights into how to keep the cardiac system ticking. Sometimes the eurekas are justified, sometimes not. The annual meeting of the American Heart Association in Florida last week was so full of news it was hard to keep the breakthroughs straight. Here are the highlights:

WHEN GOOD CHOLESTEROL ISN'T

The "good cholesterol" you hope will turn up in your blood test has that name for a reason. More properly known as high-density lipoprotein (HDL), it can prevent the damage done by its evil twin, low-density lipoprotein (LDL). The latter clogs blood vessels by combining with oxygen to form a substance that sets off alarms in the immune system. White blood cells rush to attack it, and the whole mess forms into sticky globs called plaques that cling to vessel walls like mineral deposits in a water pipe. When these deposits break off and blood clots around them, the flow can shut off entirely, leading to heart attack or stroke.

HDL is good because it keeps LDL from combining with oxygen in the first place. But doctors at UCLA studying HDL in mice have found that when the immune system is under stress--after surgery, for example, or during a major infection--HDL stops producing an enzyme called paraoxynase and thus loses its antioxidant properties. When good cholesterol goes bad, moreover, it goes really bad. Not only does it stop protecting the body against LDL, but it also seems to goad the immune system into forming plaques even more quickly.

The new insight into what makes good turn bad might help doctors make good cholesterol even better. It may also point the way to better drugs and explain why aspirin helps prevent heart attacks. Besides its well-known action of thinning the blood and making clotting less likely, aspirin may also tone down the inflammation that leads to plaque formation.

ROLLING THE DICE

Living through a heart attack has always been something of a crapshoot, and now that seems almost literally true. According to a new study, patients experiencing cardiac arrhythmia have a better chance of surviving if the crisis occurs in a casino or even an airplane than in a doctor's office. The reason? Most doctors just aren't equipped to handle the problem.

Physician Mary Ann Peberdy of the Medical College of Virginia conducted a survey of 93 doctors' offices to determine how many of them had a heart defibrillator on hand. The answer turned out to be not many. Of the 51 offices that responded, only six had bothered to purchase the $3,500 piece of equipment, and only three had a nurse on staff trained in cardiac life support. By contrast, Las Vegas casinos--rarely regarded as oases of good health--are increasingly making it a point to have defibrillators and medical teams on-site at all times.

"Airlines are putting defibrillators on planes," says Peberdy, "and one Las Vegas casino recently saved three people with cardiac arrest." For the medical community, better cardiac preparedness could come relatively cheap. Last year Peberdy saw to it that all five buildings at her medical school were provided with defibrillators and teams of nurses trained to use them. The cost: about a nickel per paying patient.

DRILLING THE HEART WITH LASER BEAMS