Heart failure 101. .

Heart failure is a condition in which the heart cannot pump enough blood to meet the needs of the body. It is usually diagnosed only after heart disease. In the past it was thought that a weak heart muscle--one unable to pump blood effectively--was necessary for a diagnosis; we now know that up to one-half of patients with heart failure instead have a stiff heart muscle, which impedes proper filling of the heart's chamber.

Symptoms include difficulty breathing, easy fatigue or swelling of the feet. Coronary artery disease and high blood pressure are the most common causes for those over 40. Sudden strenuous effort, too much sodium in the diet and sudden emotional upset can precipitate symptoms of heart failure. Diuretics, oxygen, surgery and low-sodium diets treat the symptoms, while ACE inhibitors and beta blocking drugs prolong life and reduce hospitalizations. Most recently, exercise programs are being developed for patients with heart failure.

Earlier detection than ever. Usually a diagnosis of heart failure is effectively made by medical history and physical examination alone, but in cases where the clinical picture is not straightforward, a lab test developed last July can help. Rather than suffering through prolonged uncertainty, a patient can undergo a simple blood test and find out sooner, safer and with greater reliability whether his or her heart is struggling. Strained ventricles (which are present in someone whose heart is struggling to pump enough blood) release a hormone known as BNP; high levels of BNP in the bloodstream, then, are a good indication of heart failure, with results available in 15 minutes.

Get on your feet. The American Heart Association (AHA) announced in March that exercise helps treat heart failure patients, provided they avoid sudden surges of adrenaline, and rest for a day in lieu of a workout if they are exhausted. If you have been diagnosed with heart failure, get your doctor's permission before beginning any exercise regimen.

Some people with heart failure, including those with unusual heart rhythms, may need to be monitored during exercise, but many aerobic activities -- including walking, biking, swimming and dancing -- are now said to provide several benefits to people with heart failure, including improvements in blood vessel function, exercise capacity and the flow of oxygen to muscles.

Working out 20 to 30 minutes three to five times a week is an appropriate goal, but keep in mind progression to this level will take much longer than it will someone without a heart condition. Start easy at first and slowly build intensity as you become stronger.

(Circulation: The Journal of the American Heart Association, 2003, Vol. 107, No. 8, pp. 1210-1225; Am. Journ. Med. & Sports, 2002, Vol. 4, No. 6, pp. 459-460; New Eng. Journ. Med., 2002, Vol. 347, No. 3, pp. 161-67)