Tuesday, May 09, 2006
This week's article:
How exercise helps heart failure patients
May 04 (HealthCentersOnline) - A small study may help explain why aerobic training helps to reverse the abnormal heart patterns that appear in patients after experiencing heart failure.
Heart failure is chronic condition in which at least one chamber of the heart is not pumping well enough to meet the body's needs. This leads to congestion in the lungs or pulmonary blood vessels and may cause fluid to back up in the lungs, legs and ankles.
Previous research has demonstrated that aerobic exercise can help a person with heart failure feel and function better. Now, new research suggests that this response works by suppressing certain neurohormones that cause many of the severe symptoms of heart failure.
Following certain cardiac events (e.g., heart attack), the body works to protect itself in the short term by increasing its production of certain types of B-type natriuretic peptides (BNP). These neurohormones constrict blood vessels and help heart cells to retain sodium, which allows the heart to continue to pump blood effectively.
However, over a period of time an imbalance of the BNP neurohormones can become detrimental, leading to irregular heart rhythms, tissue buildup and the accumulation of fluid in the heart.
Researchers from Italy have found that aerobic exercise helps to improve the effects of heart failure by lowering some types of BNP. The researchers studied 47 heart failure patients who had entered a nine-month aerobic training program. The 44 patients who completed the program reported an improvement in their quality of life significantly greater than a similar control group (that did not include heart failure patients). Testing also revealed the heart failure patients had lowered levels of three types of BNP.
"Reversing neurohormonal activation by physical training adds to the current clinical practice a novel non-pharmacological aid. Out of 85 patients who completed the protocol, only the 44 randomized to the training program improved functional capacity, systolic function, and quality of life, in contrast to the controls. These beneficial effects were associated with a decrease in plasma level of BNP, NT-proBNP, and norepinephrine, only in the training group," explained Claudio Passino, M.D. from the CNR Institute of Clinical Physiology in Italy, in a recent press release.
The results of the study appear in the May issue of the Journal of the American College of Cardiology.
